Juan 25/09/2015: forgotten routine for WENO5 & JPHEXT <> 1
authorJuan Escobar <juan.escobar@aero.obs-mip.fr>
Fri, 25 Sep 2015 12:25:40 +0000 (12:25 +0000)
committerPhilippe WAUTELET <philippe.wautelet@aero.obs-mip.fr>
Thu, 19 May 2016 14:44:49 +0000 (16:44 +0200)
src/MNH/advec_weno_k_3_aux.f90

index bc2170c..13c324b 100644 (file)
@@ -8,12 +8,11 @@
 !
 INTERFACE
 !
-      SUBROUTINE ADVEC_WENO_K_3_UX(HLBCX,PSRC, PRUCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_UX(HLBCX,PSRC, PRUCT, PR)
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCX  ! X direction LBC type
 !
@@ -22,18 +21,16 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRUCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 END SUBROUTINE ADVEC_WENO_K_3_UX
 !
-!                    ----------------------------
+!---------------------------------------------------------------------------------
 !
-      SUBROUTINE ADVEC_WENO_K_3_MX(HLBCX,PSRC, PRUCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_MX(HLBCX,PSRC, PRUCT, PR)
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCX  ! X direction LBC type
 !
@@ -42,18 +39,16 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRUCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 END SUBROUTINE ADVEC_WENO_K_3_MX
 !
-!                     ---------------------------
+!---------------------------------------------------------------------------------
 !
-      SUBROUTINE ADVEC_WENO_K_3_VY(HLBCY,PSRC, PRVCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_VY(HLBCY,PSRC, PRVCT, PR)
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCY  ! Y direction LBC type
 !
@@ -63,18 +58,16 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRVCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 END SUBROUTINE ADVEC_WENO_K_3_VY
 !
-!                  ------------------------------
+!---------------------------------------------------------------------------------
 !
-      SUBROUTINE ADVEC_WENO_K_3_MY(HLBCY,PSRC, PRVCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_MY(HLBCY,PSRC, PRVCT, PR)
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 CHARACTER (LEN=4), DIMENSION(2), INTENT(IN) :: HLBCY  ! Y direction LBC type
 !
@@ -83,11 +76,10 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRVCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 END SUBROUTINE ADVEC_WENO_K_3_MY
 !
-!                     -------------------------------
+!---------------------------------------------------------------------------------
 !
 FUNCTION WENO_K_3_WZ(PSRC, PRWCT) RESULT(PR)
 !
@@ -99,7 +91,7 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: PR
 !
 END FUNCTION WENO_K_3_WZ
 !
-!                      ------------------------------
+!---------------------------------------------------------------------------------
 !
 FUNCTION WENO_K_3_MZ(PSRC, PRWCT) RESULT(PR)
 !
@@ -118,7 +110,7 @@ END MODULE MODI_ADVEC_WENO_K_3_AUX
 !-----------------------------------------------------------------------------
 !
 !     ############################################################
-      SUBROUTINE ADVEC_WENO_K_3_UX(HLBCX,PSRC, PRUCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_UX(HLBCX,PSRC, PRUCT, PR)
 !     ############################################################
 !!
 !!**** Computes PRUCT * PUT. Upstream fluxes of U in X direction.  
@@ -131,13 +123,17 @@ END MODULE MODI_ADVEC_WENO_K_3_AUX
 !!
 !!    MODIFICATIONS
 !!    -------------
+!!    T. Lunet 02/10/2014:  Correction of periodic boudary conditions
+!!       Change of structure in order to adapt WENO to NHALOK
+!!       Suppression of second layer HALO pointers
+!!       Complete code documentation
+!!      J.Escobar : 25/09/2015 : WENO5 & JPHEXT <> 1 
 !!
 !-------------------------------------------------------------------------------
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 IMPLICIT NONE
 !
@@ -150,13 +146,12 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRUCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 !*       0.2   Declarations of local variables :
 !
 INTEGER :: IIB,IJB    ! Begining useful area in x,y,z directions
 INTEGER :: IIE,IJE    ! End useful area in x,y,z directions
-INTEGER:: IW,IE,IWF,IEF   ! Coordinate of third order diffusion area
+INTEGER :: IW,IE      ! Physical boundary index
 !
 INTEGER:: ILUOUT,IRESP   ! for prints
 !
@@ -165,7 +160,6 @@ INTEGER:: ILUOUT,IRESP   ! for prints
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -174,19 +168,13 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBPOS1, ZBPOS2, ZBPOS3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 !
-! WENO weights
+! WENO non-normalized weights
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMN1, ZOMN2, ZOMN3
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
+! EPSILON for weno weights calculation
+! 
 REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !-----------------------------------------------------------------------------
@@ -196,7 +184,6 @@ REAL, PARAMETER :: ZEPS = 1.0E-15
 CALL GET_INDICE_ll(IIB,IJB,IIE,IJE)
 !
 !-------------------------------------------------------------------------------
-!
 !*       0.4.   INITIALIZE THE FIELD 
 !               ---------------------
 !
@@ -222,536 +209,560 @@ ZOMN2   = 0.0
 ZOMN3   = 0.0 
 !
 !-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
+IW=IIB
+IE=IIE
 !
-SELECT CASE ( HLBCX(1) ) ! X direction LBC type: (1) for left side
-!
-!*       1.1    CYCLIC CASE IN THE X DIRECTION:
-!
-CASE ('CYCL')          ! In that case one must have HLBCX(1) == HLBCX(2)
-!
-  IF(NHALO == 1) THEN
-    IW=IIB
-    IE=IIE
-  ELSE
-    CALL FMLOOK_ll(CLUOUT0,CLUOUT0,ILUOUT,IRESP)
-    WRITE(ILUOUT,*) 'ERROR : 3rd order advection in CYCLic case '
-    WRITE(ILUOUT,*) 'cannot be used with NHALO=2'
-    CALL ABORT
-    STOP
-  END IF
-!
-! r: many left cells in regard to 'i' cell for each stencil
-!
-! intermediate fluxes at the mass point on Ugrid u(i+1/2,j,k) for positive wind
-! case (left to the right)
-! (r=2 for the first stencil ZFPOS1, r=1 for the second ZFPOS2 and
-!  r=0 for the last ZFPOS3)
-!
-  ZFPOS1(IW+1:IE-1,:,:) = 1./6 * (2.0*PSRC(IW-1:IE-3,:,:) - &
-                    7.0*PSRC(IW:IE-2,:,:) + 11.0*PSRC(IW+1:IE-1,:,:))
-  ZFPOS1(IW,       :,:) = 1./6 * (2.0*TPHALO2%WEST(:,:)   - &
-                    7.0*PSRC(IW-1,   :,:) + 11.0*PSRC(IW,       :,:))
-  ZFPOS1(IW-1,     :,:) = 0.5  * (3.0*PSRC(IW-1     ,:,:) - TPHALO2%WEST(:,:))
-  ZFPOS1(IE,       :,:) = 0.5  * (3.0*PSRC(IE       ,:,:) - PSRC(IE-1,   :,:))
-  ZFPOS1(IE+1,     :,:) = 0.5  * (3.0*PSRC(IE+1     ,:,:) - PSRC(IE,     :,:))
-!
-!
-  ZFPOS2(IW:IE-1,:,:) = 1./6 * (-1.0*PSRC(IW-1:IE-2,:,:) + 5.0*PSRC(IW:IE-1,:,:) + 2.0*PSRC(IW+1:IE,:,:))
-  ZFPOS2(IW-1,   :,:) = 0.5 * (PSRC(IW-1     ,:,:) + PSRC(IW,     :,:))
-  ZFPOS2(IE,     :,:) = 0.5 * (PSRC(IE       ,:,:) + PSRC(IE+1,   :,:))
-  ZFPOS2(IE+1,   :,:) = 0.5 * (PSRC(IE+1     ,:,:) + TPHALO2%EAST(:,:))
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IW+1 -> IE-2
+! Computation at the mass point on Ugrid u(i+1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-  ZFPOS3(IW:IE-1,:,:) = 1./6 * (2.0*PSRC(IW:IE-1,:,:) + 5.0*PSRC(IW+1:IE,:,:) &
-                        - PSRC(IW+2:IE+1,:,:))
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-2, i-1, i
+ZFPOS1(IW+1:IE-2,:,:) = 1./6.   * (2.0*PSRC(IW-1:IE-4,:,:) - 7.0*PSRC(IW:IE-3,:,:) + 11.0*PSRC(IW+1:IE-2,:,:)) ! Flux
+ZBPOS1(IW+1:IE-2,:,:) = 13./12. * (    PSRC(IW-1:IE-4,:,:) - 2.0*PSRC(IW:IE-3,:,:) +      PSRC(IW+1:IE-2,:,:))**2 & 
+                       + 1./4    * (    PSRC(IW-1:IE-4,:,:) - 4.0*PSRC(IW:IE-3,:,:) + 3.0* PSRC(IW+1:IE-2,:,:))**2 ! Smoothness indicator
+ZOMP1(IW+1:IE-2,:,:)  = 1./10. /  (ZEPS + ZBPOS1(IW+1:IE-2,:,:))**2
+!
+! Second positive stencil, needs indices i-1, i, i+1
+ZFPOS2(IW+1:IE-2,:,:) = 1./6.  * (-1.0*PSRC(IW:IE-3,:,:) + 5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))! Flux
+ZBPOS2(IW+1:IE-2,:,:) = 13./12 * (     PSRC(IW:IE-3,:,:) - 2.0*PSRC(IW+1:IE-2,:,:) +     PSRC(IW+2:IE-1,:,:))**2 &
+                         + 1./4   * (  PSRC(IW:IE-3,:,:) - PSRC(IW+2:IE-1,:,:))**2! Smoothness indicator
+ZOMP2(IW+1:IE-2,:,:)  = 3./5. /  (ZEPS + ZBPOS2(IW+1:IE-2,:,:))**2
+!
+! Third positive stencil, needs indices i, i+1, i+2
+ZFPOS3(IW+1:IE-2,:,:) = 1./6   * (2.0*PSRC(IW+1:IE-2,:,:) + 5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,:,:))! Flux
+ZBPOS3(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW+1:IE-2,:,:) - 2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 &
++ 1./4   * (3.0*PSRC(IW+1:IE-2,:,:) - 4.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2! Smoothness indicator
+ZOMP3(IW+1:IE-2,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW+1:IE-2,:,:))**2
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i+1, i+2, i+3
+ZFNEG1(IW+1:IE-2,:,:) = 1./6.   * (11.0*PSRC(IW+2:IE-1,:,:) - 7.0*PSRC(IW+3:IE,:,:) + 2.0*PSRC(IW+4:IE+1,:,:)) ! Flux
+ZBNEG1(IW+1:IE-2,:,:) = 13./12. * (     PSRC(IW+2:IE-1,:,:) - 2.0*PSRC(IW+3:IE,:,:) +     PSRC(IW+4:IE+1,:,:))**2 & 
+                        + 1./4   * (3.0* PSRC(IW+2:IE-1,:,:) - 4.0*PSRC(IW+3:IE,:,:) +     PSRC(IW+4:IE+1,:,:))**2 ! Smoothness indicator
+ZOMN1(IW+1:IE-2,:,:)  = 1./10. /  (ZEPS + ZBNEG1(IW+1:IE-2,:,:))**2
+!
+! Second negative stencil, needs indices i, i+1, i+2
+ZFNEG2(IW+1:IE-2,:,:) = 1./6.  * (2.0*PSRC(IW+1:IE-2,:,:) + 5.0*PSRC(IW+2:IE-1,:,:) - 1.0*PSRC(IW+3:IE,:,:))! Flux
+ZBNEG2(IW+1:IE-2,:,:) = 13./12 * (    PSRC(IW+1:IE-2,:,:) - 2.0*PSRC(IW+2:IE-1,:,:) +     PSRC(IW+3:IE,:,:))**2 &
+                         + 1./4   * (    PSRC(IW+1:IE-2,:,:) -  PSRC(IW+3:IE,:,:))**2! Smoothness indicator
+ZOMN2(IW+1:IE-2,:,:)  = 3./5. /  (ZEPS + ZBNEG2(IW+1:IE-2,:,:))**2! Non-normalized weight
+!
+! Third negative stencil, needs indices i-1, i, i+1
+ZFNEG3(IW+1:IE-2,:,:) = 1./6   * (-1.0*PSRC(IW:IE-3,:,:) + 5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))! Flux
+ZBNEG3(IW+1:IE-2,:,:) = 13./12 * ( PSRC(IW:IE-3,:,:) - 2.0*PSRC(IW+1:IE-2,:,:) +    PSRC(IW+2:IE-1,:,:))**2 &
+                          + 1./4   * (     PSRC(IW:IE-3,:,:) - 4.0*PSRC(IW+1:IE-2,:,:) + 3.0*PSRC(IW+2:IE-1,:,:))**2! Smoothness indicator
+ZOMN3(IW+1:IE-2,:,:)  = 3./10. / (ZEPS + ZBNEG3(IW+1:IE-2,:,:))**2! Non-normalized weight
+!
+!
+! ----- Total flux -----
+!
+PR(IW+1:IE-2,:,:) = (ZOMP1(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ZOMP2(IW+1:IE-2,:,:)+ZOMP3(IW+1:IE-2,:,:)) &
+                    * ZFPOS1(IW+1:IE-2,:,:) + &
+                      ZOMP2(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ZOMP2(IW+1:IE-2,:,:)+ZOMP3(IW+1:IE-2,:,:)) &
+                    * ZFPOS2(IW+1:IE-2,:,:) + & 
+                      ZOMP3(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ZOMP2(IW+1:IE-2,:,:)+ZOMP3(IW+1:IE-2,:,:)) &
+                    * ZFPOS3(IW+1:IE-2,:,:)) &
+                    * (0.5+SIGN(0.5,PRUCT(IW+1:IE-2,:,:))) &
+                  + (ZOMN1(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+ZOMN3(IW+1:IE-2,:,:)) &
+                   * ZFNEG1(IW+1:IE-2,:,:)  &
+                     + ZOMN2(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+ZOMN3(IW+1:IE-2,:,:)) &
+                   * ZFNEG2(IW+1:IE-2,:,:)  &
+                     + ZOMN3(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+ZOMN3(IW+1:IE-2,:,:)) &
+                    * ZFNEG3(IW+1:IE-2,:,:))  & 
+                    * (0.5-SIGN(0.5,PRUCT(IW+1:IE-2,:,:)))
 !
+!-------------------------------------------------------------------------------
+!*       1.2.   West border
+!               ---------------------
 !
-! r: many left cells in regard to 'i+1' cell for each stencil
+IF( LWEST_ll() .AND. .FALSE. ) THEN 
+!-----------------------------------------------------------------------------
+! West border is physical -- IW,IW-1
+!-----------------------------------------------------------------------------
+SELECT CASE (HLBCX(1)) ! X direction LBC type on left side
 ! 
-! intermediate flux at the mass point on Ugrid (i+1/2,j,k)=((i+1)-1/2,j,k) for 
-! negative wind case (right to the left)
-! (r=2 for the last stencil ZFNEG3=ZFPOS2, r=1 for the second ZFNEG2=ZFPOS3 
-!  and r=0 for the first ZFNEG1)  
-!
-  ZFNEG1(IW:IE-2,:,:) = 1./6 * (11.0*PSRC(IW+1:IE-1,:,:) - &
-                        7.0*PSRC(IW+2:IE,:,:) + 2.0*PSRC(IW+3:IE+1,:,:))
-  ZFNEG1(IE-1,   :,:) = 1./6 * (11.0*PSRC(IE,       :,:) - &
-                        7.0*PSRC(IE+1,   :,:) + 2.0*TPHALO2%EAST(:,:))
-  ZFNEG1(IE,  :,:) = 0.5 * (3.0*PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))
-  ZFNEG1(IE+1,:,:) = - 999.
-  ZFNEG1(IW-1,:,:) = 0.5 * (3.0*PSRC(IW,  :,:) - PSRC(IW+1,   :,:))
+CASE ('CYCL')
+!---------------------------------------------------------------------------
+! Periodic boundary condition
+!---------------------------------------------------------------------------
 !
+IF( LEAST_ll() .AND. .FALSE. ) THEN! East boundary is physical (monoproc)
+!
+! First positive stencil, needs indices i-2, i-1, i 
+ZFPOS1(IW,:,:)  = 1./6. * (2.0*PSRC(IE,:,:)   - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:))! Flux IW
+ZFPOS1(IW-1,:,:) = 1./6. * (2.0*PSRC(IE-1,:,:) - 7.0*PSRC(IE,:,:)   + 11.0*PSRC(IW-1,:,:))! Flux IW-1
+ZBPOS1(IW,:,:)  = 13./12. * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+ + 1./4    * (PSRC(IE,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW
+ZBPOS1(IW-1,:,:) = 13./12. * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IW-1,:,:))**2 & 
+ + 1./4    * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IW-1,:,:))**2 ! Smoothness indicator IW-1
+ZOMP1(IW-1:IW,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW-1:IW,:,:))**2! Non-normalized weight IW,IW-1
+!
+! Second positive stencil, needs indices i-1, i, i+1
+ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:))! Flux IW
+ZFPOS2(IW-1,:,:) = 1./6.* (-1.0*PSRC(IE,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW-1
+ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+ + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2! Smoothness indicator IW
+ZBPOS2(IW-1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+ + 1./4   * (PSRC(IE,:,:) -                      PSRC(IW,:,:))**2! Smoothness indicator IW-1
+ZOMP2(IW-1:IW,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW-1:IW,:,:))**2! Non-normalized weight IW,IW-1
+!
+! Third negative stencil, needs indices i-1, i, i+1
+ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:))! Flux IW
+ZFNEG3(IW-1,:,:) = 1./6 * (-1.0*PSRC(IE,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:))! Flux IW-1
+ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+   + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2! Smoothness indicator IW
+ZBNEG3(IW-1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+   + 1./4   * (PSRC(IE,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2! Smoothness indicator IW-1
+ZOMN3(IW-1:IW,:,:) = 3./10. / (ZEPS + ZBNEG3(IW-1:IW,:,:))**2! Non-normalized weight IW,IW-1
 ! 
-  ZFNEG2(IW:IE-1,:,:) = 1./6 * (2.0*PSRC(IW:IE-1,:,:) +    &
-                        5.0*PSRC(IW+1:IE,:,:) - PSRC(IW+2:IE+1,:,:))
-  ZFNEG2(IE,  :,:) = 0.5 * (PSRC(IE,   :,:) + PSRC(IE+1,:,:))
-  ZFNEG2(IE+1,:,:) = 0.5 * (PSRC(IE+1, :,:) + TPHALO2%EAST(:,:))
-  ZFNEG2(IW-1,:,:) = 0.5 * (PSRC(IW-1, :,:) + PSRC(IW,:,:))
-!
-!
-  ZFNEG3(IW:IE-1,:,:) = 1./6 * (-1.0*PSRC(IW-1:IE-2,:,:) + &
-                        5.0*PSRC(IW:IE-1,:,:) + 2.0*PSRC(IW+1:IE,:,:))
-!
-! smoothness indicators for positive wind case
-!
-  ZBPOS1(IW+1:IE-1,:,:) = 13./12 * (PSRC(IW-1:IE-3,:,:) - 2.0*PSRC(IW:IE-2,:,:)&
-                       + PSRC(IW+1:IE-1,:,:))**2 + 1./4 * (PSRC(IW-1:IE-3,:,:) &
-                       - 4.0*PSRC(IW:IE-2,:,:) + 3.0*PSRC(IW+1:IE-1,:,:))**2
-  ZBPOS1(IW,       :,:) = 13./12 * (TPHALO2%WEST(:,:) - 2.0*PSRC(IW-1,:,:) + &
-                          PSRC(IW,:,:))**2 + 1./4 * (TPHALO2%WEST(:,:) -     &
-                          4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2
-  ZBPOS1(IW-1,   :,:) = (PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))**2
-  ZBPOS1(IE,     :,:) = (PSRC(IE  ,:,:) - PSRC(IE-1,   :,:))**2
-  ZBPOS1(IE+1,   :,:) = (PSRC(IE+1,:,:) - PSRC(IE,     :,:))**2
-!
-!
-  ZBPOS2(IW:IE-1,:,:) = 13./12 * (PSRC(IW-1:IE-2,:,:) - 2.0*PSRC(IW:IE-1,:,:) +&
-   PSRC(IW+1:IE,:,:))**2 + 1./4 * (PSRC(IW-1:IE-2,:,:) - PSRC(IW+1:IE,:,:))**2
-  ZBPOS2(IW-1,:,:) = (PSRC(IW,  :,:) - PSRC(IW-1,:,:))**2
-  ZBPOS2(IE,  :,:) = (PSRC(IE+1,:,:) - PSRC(IE,  :,:))**2
-  ZBPOS2(IE+1,:,:) = (TPHALO2%EAST(:,:) - PSRC(IE+1,:,:))**2
-!
-!
-  ZBPOS3(IW:IE-1,:,:) = 13./12 * (PSRC(IW:IE-1,:,:) - 2.0*PSRC(IW+1:IE,:,:) + &
-   PSRC(IW+2:IE+1,:,:))**2 + 1./4 * ( 3.0*PSRC(IW:IE-1,:,:) -                 &
-   4.0*PSRC(IW+1:IE,:,:) + PSRC(IW+2:IE+1,:,:))**2
-!
-! smoothness indicators for negative wind case
-!       
-  ZBNEG1(IW:IE-2,:,:) = 13./12 * (PSRC(IW+1:IE-1,:,:) - 2.0*PSRC(IW+2:IE,:,:) +&
-              PSRC(IW+3:IE+1,:,:))**2 + 1./4 * ( 3.0*PSRC(IW+1:IE-1,:,:) -     &
-              4.0*PSRC(IW+2:IE,:,:) + PSRC(IW+3:IE+1,:,:))**2
-  ZBNEG1(IE-1,   :,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) +          &
-              TPHALO2%EAST(:,:))**2 + 1./4 * ( 3.0*PSRC(IE,:,:) -              &
-              4.0*PSRC(IE+1,:,:) + TPHALO2%EAST(:,:))**2
-  ZBNEG1(IE,   :,:) = (PSRC(IE+1,   :,:) - TPHALO2%EAST(:,:))**2
-  ZBNEG1(IE+1, :,:) = - 999.
-  ZBNEG1(IW-1, :,:) = (PSRC(IW,  :,:) - PSRC(IW+1,   :,:))**2
-!
-!
-  ZBNEG2(IW:IE-1,:,:) = 13./12 * (PSRC(IW:IE-1,:,:) - 2.0*PSRC(IW+1:IE,:,:) + &
-   PSRC(IW+2:IE+1,:,:))**2 + 1./4 * (PSRC(IW:IE-1,:,:) - PSRC(IW+2:IE+1,:,:))**2
-  ZBNEG2(IW-1,:,:) = (PSRC(IW-1,:,:) - PSRC(IW,  :,:))**2
-  ZBNEG2(IE  ,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,:,:))**2
-  ZBNEG2(IE+1,:,:) = (PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))**2
-!
+ELSEIF(IW>3) THEN! East boundary is proc border, with minimum 3 HALO points on west side
+!
+! First positive stencil, needs indices i-2, i-1, i 
+ZFPOS1(IW,:,:)   = 1./6. * (2.0*PSRC(IW-2,:,:)   - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:))! Flux IW
+ZFPOS1(IW-1,:,:) = 1./6. * (2.0*PSRC(IW-3,:,:) - 7.0*PSRC(IW-2,:,:)   + 11.0*PSRC(IW-1,:,:))! Flux IW-1
+ZBPOS1(IW,:,:)   = 13./12. * (PSRC(IW-1,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+ + 1./4    * (PSRC(IW-1,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW
+ZBPOS1(IW-1,:,:) = 13./12. * (PSRC(IW-3,:,:) - 2.0*PSRC(IW-2,:,:) +     PSRC(IW-1,:,:))**2 & 
+ + 1./4    * (PSRC(IW-3,:,:) - 4.0*PSRC(IW-2,:,:) + 3.0*PSRC(IW-1,:,:))**2 ! Smoothness indicator IW-1
+ZOMP1(IW-1:IW,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW-1:IW,:,:))**2! Non-normalized weight IW,IW-1
+!
+! Second positive stencil, needs indices i-1, i, i+1
+ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:))! Flux IW
+ZFPOS2(IW-1,:,:) = 1./6.* (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:))! Flux IW-1
+ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+ + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2! Smoothness indicator IW
+ZBPOS2(IW-1,:,:) = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+ + 1./4   * (PSRC(IW-2,:,:) -                      PSRC(IW,:,:))**2! Smoothness indicator IW-1
+ZOMP2(IW-1:IW,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW-1:IW,:,:))**2! Non-normalized weight IW,IW-1
+!
+! Third negative stencil, needs indices i-1, i, i+1
+ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:))! Flux IW
+ ZFNEG3(IW-1,:,:) = 1./6 * (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW-1
+ ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+        + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZBNEG3(IW-1,:,:) = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+        + 1./4   * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW-1
+ ZOMN3(IW-1:IW,:,:) = 3./10. / (ZEPS + ZBNEG3(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ELSE ! East boundary is proc border, with NHALO < 3 on west side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on west side'
+  CALL ABORT
+ ENDIF
+!
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IW,:,:)   = 1./6 * (2.0*PSRC(IW,:,:) + 5.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! Flux IW
+ ZFPOS3(IW-1,:,:) = 1./6 * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:) - PSRC(IW+1,:,:)) ! Flux IW-1
+ ZBPOS3(IW,:,:)   = 13./12 * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 ! Smoothness indicator IW
+ ZBPOS3(IW-1,:,:) = 13./12 * (    PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 ! Smoothness indicator IW-1
+ ZOMP3(IW-1:IW,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(IW,:,:)   = 1./6. * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + 2.0*PSRC(IW+3,:,:)) ! Flux IW
+ ZFNEG1(IW-1,:,:) = 1./6. * (11.0*PSRC(IW,:,:)   - 7.0*PSRC(IW+1,:,:) + 2.0*PSRC(IW+2,:,:)) ! Flux IW-1
+ ZBNEG1(IW,:,:)   = 13./12. * (    PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2  ! Smoothness indicator IW
+ ZBNEG1(IW-1,:,:) = 13./12. * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2  ! Smoothness indicator IW-1
+ ZOMN1(IW-1:IW,:,:) = 1./10. / (ZEPS + ZBNEG1(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(IW,:,:)   = 1./6. * (2.0*PSRC(IW,:,:)   + 5.0*PSRC(IW+1,:,:) - 1.0*PSRC(IW+2,:,:)) ! Flux IW
+ ZFNEG2(IW-1,:,:) = 1./6. * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   - 1.0*PSRC(IW+1,:,:)) ! Flux IW-1
+ ZBNEG2(IW,:,:)   = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (PSRC(IW,:,:) -                      PSRC(IW+2,:,:))**2 ! Smoothness indicator IW
+ ZBNEG2(IW-1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW-1
+ ZOMN2(IW-1:IW,:,:) = 3./5. / (ZEPS + ZBNEG2(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! ----- Total flux -----
+! 
+ PR(IW-1:IW,:,:) = ( ZOMP1(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS1(IW-1:IW,:,:) &
+                       + ZOMP2(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS2(IW-1:IW,:,:) & 
+                       + ZOMP3(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS3(IW-1:IW,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IW-1:IW,:,:))) &
+                    + ( ZOMN1(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG1(IW-1:IW,:,:) &
+                       + ZOMN2(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG2(IW-1:IW,:,:) &
+                       + ZOMN3(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG3(IW-1:IW,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IW-1:IW,:,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IW-1
+    PR(IW-1,:,:) = PSRC(IW-1,:,:) * (0.5+SIGN(0.5,PRUCT(IW-1,:,:))) + &
+                   PSRC(IW,:,:) * &
+                   (0.5-SIGN(0.5,PRUCT(IW-1,:,:)))
 !
-  ZBNEG3(IW:IE-1,:,:) = 13./12 * (PSRC(IW-1:IE-2,:,:) - 2.0*PSRC(IW:IE-1,:,:) +&
-                        PSRC(IW+1:IE,:,:))**2 + 1./4 * ( PSRC(IW-1:IE-2,:,:) - &
-                        4.0*PSRC(IW:IE-1,:,:) + 3.0*PSRC(IW+1:IE,:,:))**2
+!   ! WENO scheme order 3, IW
+    ZFPOS1(IW,:,:) = 0.5 * (3.0*PSRC(IW,:,:) - PSRC(IW-1,:,:)) ! First positive flux
+    ZFPOS2(IW,:,:) = 0.5 * ( PSRC(IW,:,:) + PSRC(IW+1,:,:)) ! Second positive flux
+    ZBPOS1(IW,:,:) = (PSRC(IW,:,:)   - PSRC(IW-1,:,:))**2 ! First positive smoothness indicator
+    ZBPOS2(IW,:,:) = (PSRC(IW+1,:,:) - PSRC(IW,:,:))**2  ! Second positive smoothness indicator
+!
+    ZFNEG1(IW,:,:) = 0.5 * (3.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! First negative flux
+    ZFNEG2(IW,:,:) = 0.5 * ( PSRC(IW,:,:)   + PSRC(IW+1,:,:)) ! Second negative flux
+    ZBNEG1(IW,:,:) = (PSRC(IW+1,:,:) - PSRC(IW+2,:,:))**2 ! First negative smoothness indicator
+    ZBNEG2(IW,:,:) = (PSRC(IW,:,:)   - PSRC(IW+1,:,:))**2 ! Second negative smoothness indicator
+!
+    ZOMP1(IW,:,:) = 1./3. / (ZEPS + ZBPOS1(IW,:,:))**2 ! First positive non-normalized weight
+    ZOMP2(IW,:,:) = 2./3. / (ZEPS + ZBPOS2(IW,:,:))**2 ! Second positive non-normalized weight
+    ZOMN1(IW,:,:) = 1./3. / (ZEPS + ZBNEG1(IW,:,:))**2 ! First negative non-normalized weight
+    ZOMN2(IW,:,:) = 2./3. / (ZEPS + ZBNEG2(IW,:,:))**2 ! Second negative non-normalized weight
+! 
+    PR(IW,:,:) = (ZOMN2(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG2(IW,:,:) + &
+             (ZOMN1(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG1(IW,:,:))) &
+           *(0.5-SIGN(0.5,PRUCT(IW,:,:))) + &
+     (ZOMP2(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS2(IW,:,:) + &
+     (ZOMP1(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS1(IW,:,:))) &
+     *(0.5+SIGN(0.5,PRUCT(IW,:,:)))  ! Total flux
+! 
+ END SELECT ! SELECT CASE (HLBCX(1)) ! X direction LBC type on left side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! West border is proc border -- IW,IW-1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+!
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(IW,:,:)   = 1./6. * (2.0*PSRC(IW-2,:,:) - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:)) ! Flux IW
+ ZFPOS1(IW-1,:,:) = 1./6. * (2.0*PSRC(IW-3,:,:) - 7.0*PSRC(IW-2,:,:) + 11.0*PSRC(IW-1,:,:)) ! Flux IW-1
+ ZBPOS1(IW,:,:)   = 13./12. * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+        + 1./4    * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2   ! Smoothness indicator IW
+ ZBPOS1(IW-1,:,:) = 13./12. * (PSRC(IW-3,:,:) - 2.0*PSRC(IW-2,:,:) +     PSRC(IW-1,:,:))**2 & 
+        + 1./4    * (PSRC(IW-3,:,:) - 4.0*PSRC(IW-2,:,:) + 3.0*PSRC(IW-1,:,:))**2  ! Smoothness indicator IW-1
+ ZOMP1(IW-1:IW,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW
+ ZFPOS2(IW-1,:,:) = 1./6.* (-1.0*PSRC(IW-2,:,:) + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW-1
+ ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZBPOS2(IW-1,:,:) = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IW-2,:,:) -                      PSRC(IW,:,:))**2 ! Smoothness indicator IW-1
+ ZOMP2(IW-1:IW,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW-1:IW,:,:))**2  ! Non-normalized weight IW,IW-1
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IW,:,:)   = 1./6 * (2.0*PSRC(IW,:,:) + 5.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! Flux IW
+ ZFPOS3(IW-1,:,:) = 1./6 * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:) - PSRC(IW+1,:,:)) ! Flux IW-1
+ ZBPOS3(IW,:,:)   = 13./12 * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 ! Smoothness indicator IW
+ ZBPOS3(IW-1,:,:) = 13./12 * (    PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 ! Smoothness indicator IW-1
+ ZOMP3(IW-1:IW,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(IW,:,:)   = 1./6. * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + 2.0*PSRC(IW+3,:,:)) ! Flux IW
+ ZFNEG1(IW-1,:,:) = 1./6. * (11.0*PSRC(IW,:,:)   - 7.0*PSRC(IW+1,:,:) + 2.0*PSRC(IW+2,:,:)) ! Flux IW-1
+ ZBNEG1(IW,:,:)   = 13./12. * (    PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2  ! Smoothness indicator IW
+ ZBNEG1(IW-1,:,:) = 13./12. * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2  ! Smoothness indicator IW-1
+ ZOMN1(IW-1:IW,:,:) = 1./10. / (ZEPS + ZBNEG1(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(IW,:,:)   = 1./6. * (2.0*PSRC(IW,:,:)   + 5.0*PSRC(IW+1,:,:) - 1.0*PSRC(IW+2,:,:)) ! Flux IW
+ ZFNEG2(IW-1,:,:) = 1./6. * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   - 1.0*PSRC(IW+1,:,:)) ! Flux IW-1
+ ZBNEG2(IW,:,:)   = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (PSRC(IW,:,:) -                      PSRC(IW+2,:,:))**2 ! Smoothness indicator IW
+ ZBNEG2(IW-1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW-1
+ ZOMN2(IW-1:IW,:,:) = 3./5. / (ZEPS + ZBNEG2(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW
+ ZFNEG3(IW-1,:,:) = 1./6 * (-1.0*PSRC(IW-2,:,:) + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW-1
+ ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+        + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZBNEG3(IW-1,:,:) = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+        + 1./4   * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW-1
+ ZOMN3(IW-1:IW,:,:) = 3./10. / (ZEPS + ZBNEG3(IW-1:IW,:,:))**2 ! Non-normalized weight IW,IW-1
+!
+ ! ----- Total flux -----
+! 
+ PR(IW-1:IW,:,:) = ( ZOMP1(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS1(IW-1:IW,:,:) &
+                       + ZOMP2(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS2(IW-1:IW,:,:) & 
+                       + ZOMP3(IW-1:IW,:,:)/(ZOMP1(IW-1:IW,:,:)+ZOMP2(IW-1:IW,:,:)+ZOMP3(IW-1:IW,:,:)) * ZFPOS3(IW-1:IW,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IW-1:IW,:,:))) &
+                    + ( ZOMN1(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG1(IW-1:IW,:,:) &
+                       + ZOMN2(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG2(IW-1:IW,:,:) &
+                       + ZOMN3(IW-1:IW,:,:)/(ZOMN1(IW-1:IW,:,:)+ZOMN2(IW-1:IW,:,:)+ZOMN3(IW-1:IW,:,:)) * ZFNEG3(IW-1:IW,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IW-1:IW,:,:)))
 !
-! WENO weights
+ END IF ! NHALO
 !
-  ZOMP1(IW:IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW:IE-1,:,:))**2
-  ZOMP2(IW:IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW:IE-1,:,:))**2
-  ZOMP3(IW:IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW:IE-1,:,:))**2
-  ZOMN1(IW:IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW:IE-1,:,:))**2
-  ZOMN2(IW:IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW:IE-1,:,:))**2
-  ZOMN3(IW:IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW:IE-1,:,:))**2
-!
-  ZOMP1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW-1,:,:))**2
-  ZOMP2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW-1,:,:))**2
-  ZOMP1(IE,  :,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE,  :,:))**2
-  ZOMP2(IE,  :,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE,  :,:))**2
-  ZOMP1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE+1,:,:))**2
-  ZOMP2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE+1,:,:))**2
-  ZOMN1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW-1,:,:))**2
-  ZOMN2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW-1,:,:))**2
-  ZOMN1(IE,  :,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE,  :,:))**2
-  ZOMN2(IE,  :,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE,  :,:))**2
-  ZOMN1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE+1,:,:))**2
-  ZOMN2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE+1,:,:))**2
-!
-! WENO fluxes (5th order)
-!
-  PR(IW:IE-1,:,:) = (ZOMP2(IW:IE-1,:,:)/(ZOMP1(IW:IE-1,:,:)+ZOMP2(IW:IE-1,:,:)+&
-                     ZOMP3(IW:IE-1,:,:)) * ZFPOS2(IW:IE-1,:,:) &
-                   + ZOMP1(IW:IE-1,:,:)/(ZOMP1(IW:IE-1,:,:)+ZOMP2(IW:IE-1,:,:)+&
-                     ZOMP3(IW:IE-1,:,:)) * ZFPOS1(IW:IE-1,:,:) & 
-                   + ZOMP3(IW:IE-1,:,:)/(ZOMP1(IW:IE-1,:,:)+ZOMP2(IW:IE-1,:,:)+&
-                     ZOMP3(IW:IE-1,:,:)) * ZFPOS3(IW:IE-1,:,:))&
-                   * (0.5+SIGN(0.5,PRUCT(IW:IE-1,:,:)))        &
-                  + (ZOMN2(IW:IE-1,:,:)/(ZOMN1(IW:IE-1,:,:)+ZOMN2(IW:IE-1,:,:)+&
-                     ZOMN3(IW:IE-1,:,:)) * ZFNEG2(IW:IE-1,:,:) &
-                   + ZOMN1(IW:IE-1,:,:)/(ZOMN1(IW:IE-1,:,:)+ZOMN2(IW:IE-1,:,:)+&
-                     ZOMN3(IW:IE-1,:,:)) * ZFNEG1(IW:IE-1,:,:) &
-                   + ZOMN3(IW:IE-1,:,:)/(ZOMN1(IW:IE-1,:,:)+ZOMN2(IW:IE-1,:,:)+&
-                     ZOMN3(IW:IE-1,:,:)) * ZFNEG3(IW:IE-1,:,:))&
-                   * (0.5-SIGN(0.5,PRUCT(IW:IE-1,:,:)))
-!
-! WENO fluxes (3rd order)
-!
-  PR(IW-1,:,:) = (ZOMN2(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) * & 
-                  ZFNEG2(IW-1,:,:)     &
-               + (ZOMN1(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) * &
-                  ZFNEG1(IW-1,:,:))) * &
-               (0.5-SIGN(0.5,PRUCT(IW-1,:,:)))                        &
-               + (ZOMP2(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) * &
-               ZFPOS2(IW-1,:,:)     &
-               + (ZOMP1(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) * &
-               ZFPOS1(IW-1,:,:))) * &
-               (0.5+SIGN(0.5,PRUCT(IW-1,:,:)))
-!
-  PR(IE,  :,:) = (ZOMN2(IE,  :,:)/(ZOMN1(IE,  :,:)+ZOMN2(IE,  :,:)) * &
-               ZFNEG2(IE,  :,:)     &
-               + (ZOMN1(IE,  :,:)/(ZOMN1(IE,  :,:)+ZOMN2(IE,  :,:)) * &
-               ZFNEG1(IE,  :,:))) * &
-               (0.5-SIGN(0.5,PRUCT(IE,  :,:)))                        &
-               + (ZOMP2(IE,  :,:)/(ZOMP1(IE,  :,:)+ZOMP2(IE,  :,:)) * &
-               ZFPOS2(IE,  :,:)     &
-               + (ZOMP1(IE,  :,:)/(ZOMP1(IE,  :,:)+ZOMP2(IE,  :,:)) * &
-               ZFPOS1(IE,  :,:))) * &
-               (0.5+SIGN(0.5,PRUCT(IE,  :,:)))
-!
-  PR(IE+1,:,:) = (ZOMN2(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) * &
-               ZFNEG2(IE+1,:,:)     &
-               + (ZOMN1(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) * &
-               ZFNEG1(IE+1,:,:))) * &
-               (0.5-SIGN(0.5,PRUCT(IE+1,:,:)))                        &
-               + (ZOMP2(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) * &
-               ZFPOS2(IE+1,:,:)     &
-               + (ZOMP1(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) * &
-               ZFPOS1(IE+1,:,:))) * &
-               (0.5+SIGN(0.5,PRUCT(IE+1,:,:)))
-!
-!
-!       OPEN, WALL, NEST CASE IN THE X DIRECTION
-!
-CASE ('OPEN','WALL','NEST')
-!
-  IW=IIB
-  IE=IIE
-!
-!  LATERAL BOUNDARY CONDITIONS
-!  AT THE PHYSICAL BORDER: USE A FIRST ORDER UPSTREAM WENO SCHEME AT THE POINTS: IW-1, 
-! IE /AND/ A THIRD ORDER WENO SCHEME AT THE POINTS: IW, IE-1
-!  AT THE PROC. BORDER: A THIRD ORDER UPSTREAM WENO SCHEME AT THE POINTS: IW-1, IE  /AND/ 
-! A FIFTH ORDER WENO SCHEME AT THE POINTS: IW, IE-1
-!
-!   PHYSICAL BORDER (WEST)
-!
-  IF(LWEST_ll()) THEN
-!
-!   FISRT ORDER WENO SCHEME
+END IF ! IF(LWEST_ll()) 
 !
-    PR(IW-1,:,:) = PSRC(IW-1,:,:) * (0.5+SIGN(0.5,PRUCT(IW-1,:,:))) + &
-                   PSRC(IW,:,:) * &
-                   (0.5-SIGN(0.5,PRUCT(IW-1,:,:)))
+!-------------------------------------------------------------------------------
+!*       1.3.   East border
+!               ---------------------
 !
-!   THIRD ORDER WENO SCHEME
-!
-    ZFPOS1(IW,:,:) = 0.5  * (3.0*PSRC(IW,:,:) - PSRC(IW-1,:,:))
-    ZFPOS2(IW,:,:) = 0.5 * (PSRC(IW     ,:,:) + PSRC(IW+1,:,:))
-    ZBPOS1(IW,:,:) = (PSRC(IW,:,:) - PSRC(IW-1,:,:))**2
-    ZBPOS2(IW,:,:) = (PSRC(IW+1,  :,:) - PSRC(IW,:,:))**2
-!
-    ZFNEG1(IW,:,:) = 0.5 * (3.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:))
-    ZFNEG2(IW,:,:) = 0.5 * (PSRC(IW,      :,:) + PSRC(IW+1,:,:))
-    ZBNEG1(IW,:,:) = (PSRC(IW+1,:,:) - PSRC(IW+2,:,:))**2
-    ZBNEG2(IW,:,:) = (PSRC(IW,  :,:) - PSRC(IW+1,:,:))**2
-!
-    ZOMP1(IW,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW,:,:))**2
-    ZOMP2(IW,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW,:,:))**2
-    ZOMN1(IW,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW,:,:))**2
-    ZOMN2(IW,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW,:,:))**2
-!
-    PR(IW,:,:) = (ZOMN2(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * &
-      ZFNEG2(IW,:,:) +  &
-       (ZOMN1(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG1(IW,:,:))) *  &
-       (0.5-SIGN(0.5,PRUCT(IW,:,:))) +                                    &
-       (ZOMP2(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS2(IW,:,:) +    &
-       (ZOMP1(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS1(IW,:,:))) *  &
-       (0.5+SIGN(0.5,PRUCT(IW,:,:)))
-!
-!    PROC. BORDER (WEST)
-!
-  ELSEIF(NHALO == 1) THEN
-!
-!   THIRD ORDER WENO SCHEME
-!
-    ZFPOS1(IW-1,:,:) = 0.5  * (3.0*PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))
-    ZFPOS2(IW-1,:,:) = 0.5 * (PSRC(IW-1,     :,:) + PSRC(IW,:,:))
-    ZBPOS1(IW-1,:,:) = (PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))**2
-    ZBPOS2(IW-1,:,:) = (PSRC(IW,  :,:) - PSRC(IW-1,:,:))**2
-!
-    ZFNEG1(IW-1,:,:) = 0.5 * (3.0*PSRC(IW,:,:) - PSRC(IW+1,:,:))
-    ZFNEG2(IW-1,:,:) = 0.5 * (PSRC(IW-1,  :,:) + PSRC(IW,  :,:))
-    ZBNEG1(IW-1,:,:) = (PSRC(IW,  :,:) - PSRC(IW+1,:,:))**2
-    ZBNEG2(IW-1,:,:) = (PSRC(IW-1,:,:) - PSRC(IW,  :,:))**2
-!
-    ZOMP1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW-1,:,:))**2
-    ZOMP2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW-1,:,:))**2
-    ZOMN1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW-1,:,:))**2
-    ZOMN2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW-1,:,:))**2
-!
-    PR(IW-1,:,:) = (ZOMN2(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) &
-               * ZFNEG2(IW-1,:,:)  &
-               + (ZOMN1(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) * &
-                 ZFNEG1(IW-1,:,:))) *&
-               (0.5-SIGN(0.5,PRUCT(IW-1,:,:)))                        &
-               + (ZOMP2(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) * &
-                 ZFPOS2(IW-1,:,:)    &
-               + (ZOMP1(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) * &
-                 ZFPOS1(IW-1,:,:))) *&
-               (0.5+SIGN(0.5,PRUCT(IW-1,:,:)))
-!
-!   FIFTH ORDER WENO SCHEME
-!
-    ZFPOS1(IW,:,:) = 1./6 * (2.0*TPHALO2%WEST(:,:) - 7.0*PSRC(IW-1,:,:) + &
-                     11.0*PSRC(IW, :,:))
-    ZFPOS2(IW,:,:) = 1./6 * (-1.0*PSRC(IW-1,  :,:) + 5.0*PSRC(IW,  :,:) + &
-                     2.0*PSRC(IW+1,:,:))
-    ZFPOS3(IW,:,:) = 1./6 * (2.0*PSRC(IW,     :,:) + 5.0*PSRC(IW+1,:,:) - &
-                     PSRC(IW+2,:,:))
-!
-    ZFNEG1(IW,:,:) = 1./6 * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + &
-                     2.0*PSRC(IW+3,:,:))
-    ZFNEG2(IW,:,:) = 1./6 * ( 2.0*PSRC(IW,  :,:) + 5.0*PSRC(IW+1,:,:) - &
-                     PSRC(IW+2,:,:))
-    ZFNEG3(IW,:,:) = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,  :,:) + &
-                     2.0*PSRC(IW+1,:,:))  
-!
-    ZBPOS1(IW,:,:) = 13./12 * (TPHALO2%WEST(:,:) - 2.0*PSRC(IW-1,:,:) + &
-                     PSRC(IW,:,:))**2 + &
-                     1./4 * (TPHALO2%WEST(:,:) - 4.0*PSRC(IW-1,:,:) + &
-                     3.0*PSRC(IW,:,:))**2
-    ZBPOS2(IW,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + &
-                     PSRC(IW+1,:,:))**2 + &
-                     1./4 * (PSRC(IW-1,:,:) - PSRC(IW+1,:,:))**2
-    ZBPOS3(IW,:,:) = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + &
-                     PSRC(IW+2,:,:))**2 + &
-                     1./4 * ( 3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + &
-                     PSRC(IW+2,:,:))**2
-!
-    ZBNEG1(IW,:,:) = 13./12 * (PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) + &
-                     PSRC(IW+3,:,:))**2 + &
-                     1./4 * ( 3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) + &
-                     PSRC(IW+3,:,:))**2
-    ZBNEG2(IW,:,:) = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + &
-                     PSRC(IW+2,:,:))**2 + &
-                     1./4 * (PSRC(IW,:,:) - PSRC(IW+2,:,:))**2    
-    ZBNEG3(IW,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + &
-                     PSRC(IW+1,:,:))**2 + &
-                     1./4 * ( PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + &
-                     3.0*PSRC(IW+1,:,:))**2
-!
-    ZOMP1(IW,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW,:,:))**2
-    ZOMP2(IW,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW,:,:))**2
-    ZOMP3(IW,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW,:,:))**2
-    ZOMN1(IW,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW,:,:))**2
-    ZOMN2(IW,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW,:,:))**2
-    ZOMN3(IW,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW,:,:))**2
-!
-    PR(IW,:,:) = (ZOMP2(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)+ &
-                  ZOMP3(IW,:,:)) * ZFPOS2(IW,:,:)      &
-                   + ZOMP1(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)+ &
-                   ZOMP3(IW,:,:)) * ZFPOS1(IW,:,:)   &
-                   + ZOMP3(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)+ &
-                   ZOMP3(IW,:,:)) * ZFPOS3(IW,:,:)) *&
-                   (0.5+SIGN(0.5,PRUCT(IW,:,:)))                 &
-                   + (ZOMN2(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)+&
-                   ZOMN3(IW,:,:)) * ZFNEG2(IW,:,:)  &
-                   + ZOMN1(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)+ &
-                   ZOMN3(IW,:,:)) * ZFNEG1(IW,:,:)   &
-                   + ZOMN3(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)+ &
-                   ZOMN3(IW,:,:)) * ZFNEG3(IW,:,:)) *&
-                   (0.5-SIGN(0.5,PRUCT(IW,:,:)))
-!
-  ENDIF
-!
-! PHYSICAL BORDER (EAST)
-!
-  IF(LEAST_ll()) THEN
+IF( LEAST_ll() .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! East border is physical -- IE-1,IE
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCX(2)) ! X direction LBC type on right side
+! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
+! 
+ IF (LWEST_ll() .AND. .FALSE. ) THEN  ! West boundary is physical (monoproc)
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE-1,:,:) = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IW,:,:)) ! Flux IE
+ ZBPOS3(IE-1,:,:) = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2  ! Smoothness indicator IE
+ ZOMP3(IE-1:IE,:,:)  = 3./10. / (ZEPS + ZBPOS3(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(IE-1,:,:) = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IE-1
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IE
+ ZBNEG1(IE-1,:,:) = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2  ! Smoothness indicator IE-1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2  ! Smoothness indicator IE
+ ZOMN1(IE-1:IE,:,:) = 1./10. / (ZEPS + ZBNEG1(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(IE-1,:,:) = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IW,:,:)) ! Flux IE
+ ZBNEG2(IE-1,:,:)  = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IW,:,:))**2  ! Smoothness indicator IE
+ ZOMN2(IE-1:IE,:,:) = 3./5. / (ZEPS + ZBNEG2(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ELSEIF(IE<=SIZE(PSRC,1)-3) THEN ! West boundary is proc border, with minimum 3 HALO points on east side
+!
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE-1,:,:) = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IE+2,:,:)) ! Flux IE
+ ZBPOS3(IE-1,:,:) = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE
+ ZOMP3(IE-1:IE,:,:)  = 3./10. / (ZEPS + ZBPOS3(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(IE-1,:,:) = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IE+2,:,:)) ! Flux IE-1
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IE+2,:,:)   + 2.0*PSRC(IE+3,:,:)) ! Flux IE
+ ZBNEG1(IE-1,:,:) = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE-1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2  ! Smoothness indicator IE
+ ZOMN1(IE-1:IE,:,:) = 1./10. / (ZEPS + ZBNEG1(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(IE-1,:,:) = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IE+2,:,:)) ! Flux IE
+ ZBNEG2(IE-1,:,:)  = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IE+2,:,:))**2  ! Smoothness indicator IE
+ ZOMN2(IE-1:IE,:,:) = 3./5. / (ZEPS + ZBNEG2(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ELSE ! West boundary is proc border, with NHALO < 3 on east side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on east side'
+  CALL ABORT
+ ENDIF
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(IE-1,:,:) = 1./6. * (2.0*PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + 11.0*PSRC(IE-1,:,:)) ! Flux IE-1
+ ZFPOS1(IE,:,:)   = 1./6. * (2.0*PSRC(IE-2,:,:) - 7.0*PSRC(IE-1,:,:) + 11.0*PSRC(IE,:,:)) ! Flux IE
+ ZBPOS1(IE-1,:,:) = 13./12. * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) +     PSRC(IE-1,:,:))**2 & 
+        + 1./4    * (PSRC(IE-3,:,:) - 4.0*PSRC(IE-2,:,:) + 3.0*PSRC(IE-1,:,:))**2  ! Smoothness indicator IE-1
+ ZBPOS1(IE,:,:)   = 13./12. * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 & 
+        + 1./4    * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2  ! Smoothness indicator IE
+ ZOMP1(IE-1:IE,:,:)  = 1./10. / (ZEPS + ZBPOS1(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(IE-1,:,:) = 1./6. * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE-1
+ ZFPOS2(IE,:,:)   = 1./6. * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZBPOS2(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + PSRC(IE,:,:))**2 &
+      + 1./4   * (PSRC(IE-2,:,:) -                      PSRC(IE,:,:))**2 ! Smoothness indicator IE-1
+ ZBPOS2(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                   PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZOMP2(IE-1:IE,:,:)  = 3./5. / (ZEPS + ZBPOS2(IE-1:IE,:,:))**2  ! Non-normalized weight IE-1,IE
+! 
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(IE-1,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE-1
+ ZFNEG3(IE,:,:)   = 1./6 * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZBNEG3(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 &
+        + 1./4   * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2 ! Smoothness indicator IE-1
+ ZBNEG3(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IE+1,:,:))**2 &
+        + 1./4   * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZOMN3(IE-1:IE,:,:) = 3./10. / (ZEPS + ZBNEG3(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! ----- Total flux -----
+! 
+ PR(IE-1:IE,:,:) = ( ZOMP1(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS1(IE-1:IE,:,:) &
+                       + ZOMP2(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS2(IE-1:IE,:,:) & 
+                       + ZOMP3(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS3(IE-1:IE,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IE-1:IE,:,:))) &
+                    + ( ZOMN1(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG1(IE-1:IE,:,:) &
+                       + ZOMN2(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG2(IE-1:IE,:,:) &
+                       + ZOMN3(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG3(IE-1:IE,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IE-1:IE,:,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IE
     PR(IE,:,:) = PSRC(IE,:,:) * (0.5+SIGN(0.5,PRUCT(IE,:,:))) + &
                  PSRC(IE+1,:,:) * &
                  (0.5-SIGN(0.5,PRUCT(IE,:,:)))
 !
-    ZFPOS1(IE-1,:,:) = 0.5 * (3.0*PSRC(IE-1,:,:) - PSRC(IE-2,:,:))
-    ZFPOS2(IE-1,:,:) = 0.5 * (PSRC(IE-1,    :,:) + PSRC(IE,  :,:))
-    ZBPOS1(IE-1,:,:) = (PSRC(IE-1,:,:) - PSRC(IE-2,:,:))**2
-    ZBPOS2(IE-1,:,:) = (PSRC(IE,  :,:) - PSRC(IE-1,:,:))**2
-!
-    ZFNEG1(IE-1,:,:) = 0.5 * (3.0*PSRC(IE,:,:) - PSRC(IE+1,:,:))
-    ZFNEG2(IE-1,:,:) = 0.5 * (PSRC(IE-1,  :,:) + PSRC(IE,  :,:))
-    ZBNEG1(IE-1,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,:,:))**2
-    ZBNEG2(IE-1,:,:) = (PSRC(IE-1,:,:) - PSRC(IE,  :,:))**2
-!
-    ZOMP1(IE-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE-1,:,:))**2
-    ZOMP2(IE-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE-1,:,:))**2
-    ZOMN1(IE-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE-1,:,:))**2
-    ZOMN2(IE-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE-1,:,:))**2
-!    
-      PR(IE-1,:,:) = (ZOMN2(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:)) * &
-               ZFNEG2(IE-1,:,:)&
-               + (ZOMN1(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:)) * &
-               ZFNEG1(IE-1,:,:))) *&
-               (0.5-SIGN(0.5,PRUCT(IE-1,:,:)))                        &
-               + (ZOMP2(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:)) * &
-               ZFPOS2(IE-1,:,:)    &
-               + (ZOMP1(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:)) * &
-               ZFPOS1(IE-1,:,:))) *&
-               (0.5+SIGN(0.5,PRUCT(IE-1,:,:)))
-!
-! PROC. BORDER (EAST)
-!
-  ELSEIF(NHALO == 1) THEN
-!
-    ZFPOS1(IE,:,:) = 0.5 * (3.0*PSRC(IE,:,:) - PSRC(IE-1,:,:))
-    ZFPOS2(IE,:,:) = 0.5 * (PSRC(IE,    :,:) + PSRC(IE+1,:,:))
-    ZBPOS1(IE,:,:) = (PSRC(IE,  :,:) - PSRC(IE-1,:,:))**2
-    ZBPOS2(IE,:,:) = (PSRC(IE+1,:,:) - PSRC(IE,  :,:))**2
-!
-    ZFNEG1(IE,:,:) = 0.5 * (3.0*PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))
-    ZFNEG2(IE,:,:) = 0.5 * (PSRC(IE,      :,:) + PSRC(IE+1,:,:))
-    ZBNEG1(IE,:,:) = (PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))**2
-    ZBNEG2(IE,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,:,:))**2
-!
-    ZOMP1(IE,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE,:,:))**2
-    ZOMP2(IE,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE,:,:))**2
-    ZOMN1(IE,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE,:,:))**2
-    ZOMN2(IE,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE,:,:))**2
-!
-    PR(IE,:,:) = (ZOMN2(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)) * ZFNEG2(IE,:,:)&
-               + (ZOMN1(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)) * ZFNEG1(IE,:,:))) *&
-               (0.5-SIGN(0.5,PRUCT(IE,:,:)))                                      &
-               + (ZOMP2(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)) * ZFPOS2(IE,:,:)    &
-               + (ZOMP1(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)) * ZFPOS1(IE,:,:))) *&
-               (0.5+SIGN(0.5,PRUCT(IE,:,:)))
-!
-!
-    ZFPOS1(IE-1,:,:) = 1./6 * (2.0 *PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + &
-                              11.0*PSRC(IE-1,:,:))
-    ZFPOS2(IE-1,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + &
-                              2.0*PSRC(IE,:,:))
-    ZFPOS3(IE-1,:,:) = 1./6 * (2.0 *PSRC(IE-1,:,:) + 5.0*PSRC(IE,  :,:) - &
-                              PSRC(IE+1,  :,:))
-!
-    ZFNEG1(IE-1,:,:) = 1./6 * (11.0*PSRC(IE,:,:) - 7.0*PSRC(IE+1,:,:) + &
-                              2.0*TPHALO2%EAST(:,:))
-    ZFNEG2(IE-1,:,:) = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - &
-                              PSRC(IE+1,:,:))
-    ZFNEG3(IE-1,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + &
-                              2.0*PSRC(IE,:,:))
-!
-    ZBPOS1(IE-1,:,:) = 13./12 * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) + &
-                       PSRC(IE-1,:,:))**2 + &
-                       1./4 * (PSRC(IE-3,:,:) - 4.0*PSRC(IE-2,:,:) + &
-                       3.0*PSRC(IE-1,:,:))**2
-    ZBPOS2(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + &
-                       PSRC(IE,:,:))**2 + &
-                       1./4 * (PSRC(IE-2,:,:) - PSRC(IE,:,:))**2
-    ZBPOS3(IE-1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + &
-                       PSRC(IE+1,:,:))**2 + &
-                       1./4 * ( 3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + &
-                       PSRC(IE+1,:,:))**2!
-    ZBNEG1(IE-1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + &
-                       TPHALO2%EAST(:,:))**2 + &
-                       1./4 * ( 3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + &
-                       TPHALO2%EAST(:,:))**2
-    ZBNEG2(IE-1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + &
-                       PSRC(IE+1,:,:))**2 + &
-                       1./4 * (PSRC(IE-1,:,:) - PSRC(IE+1,:,:))**2
-    ZBNEG3(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + &
-                       PSRC(IE,:,:))**2 + &
-                       1./4 * ( PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + &
-                       3.0*PSRC(IE,:,:))**2
-!
-    ZOMP1(IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IE-1,:,:))**2
-    ZOMP2(IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IE-1,:,:))**2
-    ZOMP3(IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IE-1,:,:))**2
-    ZOMN1(IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IE-1,:,:))**2
-    ZOMN2(IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IE-1,:,:))**2
-    ZOMN3(IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IE-1,:,:))**2
-!
-      PR(IE-1,:,:) = (ZOMP2(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:)+ &
-                   ZOMP3(IE-1,:,:)) * ZFPOS2(IE-1,:,:)   &
-                   + ZOMP1(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:)+ &
-                   ZOMP3(IE-1,:,:)) * ZFPOS1(IE-1,:,:)    &
-                   + ZOMP3(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:)+ &
-                   ZOMP3(IE-1,:,:)) * ZFPOS3(IE-1,:,:)) * &
-                   (0.5+SIGN(0.5,PRUCT(IE-1,:,:))) &
-                  + (ZOMN2(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:)+ &
-                  ZOMN3(IE-1,:,:)) * ZFNEG2(IE-1,:,:)    &
-                   + ZOMN1(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:)+ &
-                   ZOMN3(IE-1,:,:)) * ZFNEG1(IE-1,:,:)    &
-                   + ZOMN3(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:)+ &
-                   ZOMN3(IE-1,:,:)) * ZFNEG3(IE-1,:,:)) * &
-                   (0.5-SIGN(0.5,PRUCT(IE-1,:,:)))
-!
-  ENDIF
-!
-!      USE A FIFTH ORDER UPSTREAM WENO SCHEME ELSEWHERE (IW+1 --> IE-2) 
-!
-  ZFPOS1(IW+1:IE-2,:,:) = 1./6 * (2.0*PSRC(IW-1:IE-4,:,:) - &
-   7.0*PSRC(IW:IE-3,:,:) + 11.0*PSRC(IW+1:IE-2,:,:))
-  ZFPOS2(IW+1:IE-2,:,:) = 1./6 * (-1.0*PSRC(IW:IE-3,:,:) + &
-   5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))
-  ZFPOS3(IW+1:IE-2,:,:) = 1./6 * (2.0*PSRC(IW+1:IE-2,:,:) + &
-   5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,:,:))
-!
-  ZFNEG1(IW+1:IE-2,:,:) = 1./6 * (11.0*PSRC(IW+2:IE-1,:,:) - &
-   7.0*PSRC(IW+3:IE,:,:) + 2.0*PSRC(IW+4:IE+1,:,:))
-  ZFNEG2(IW+1:IE-2,:,:) = 1./6 * (2.0*PSRC(IW+1:IE-2,:,:) + &
-   5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,:,:))
-  ZFNEG3(IW+1:IE-2,:,:) = 1./6 * (-1.0*PSRC(IW:IE-3,:,:) + &
-   5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))
-!
-  ZBPOS1(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW-1:IE-4,:,:) - &
-    2.0*PSRC(IW:IE-3,:,:) + PSRC(IW+1:IE-2,:,:))**2 + &
-    1./4 * (PSRC(IW-1:IE-4,:,:) - 4.0*PSRC(IW:IE-3,:,:) + &
-    3.0*PSRC(IW+1:IE-2,:,:))**2
-  ZBPOS2(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW:IE-3,:,:) - &
-    2.0*PSRC(IW+1:IE-2,:,:) + PSRC(IW+2:IE-1,:,:))**2 + &
-    1./4 * (PSRC(IW:IE-3,:,:) - PSRC(IW+2:IE-1,:,:))**2
-  ZBPOS3(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW+1:IE-2,:,:) - &
-    2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 + &
-    1./4 * ( 3.0*PSRC(IW+1:IE-2,:,:) - 4.0*PSRC(IW+2:IE-1,:,:) &
-    + PSRC(IW+3:IE,:,:))**2
-!
-  ZBNEG1(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW+2:IE-1,:,:) - &
-    2.0*PSRC(IW+3:IE,:,:) + PSRC(IW+4:IE+1,:,:))**2 + &
-    1./4 * ( 3.0*PSRC(IW+2:IE-1,:,:) - 4.0*PSRC(IW+3:IE,:,:) + &
-    PSRC(IW+4:IE+1,:,:))**2
-  ZBNEG2(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW+1:IE-2,:,:) - &
-    2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 + &
-    1./4 * (PSRC(IW+1:IE-2,:,:) - PSRC(IW+3:IE,:,:))**2
-  ZBNEG3(IW+1:IE-2,:,:) = 13./12 * (PSRC(IW:IE-3,:,:) - &
-    2.0*PSRC(IW+1:IE-2,:,:) + PSRC(IW+2:IE-1,:,:))**2 + &
-    1./4 * ( PSRC(IW:IE-3,:,:) - 4.0*PSRC(IW+1:IE-2,:,:) + &
-    3.0*PSRC(IW+2:IE-1,:,:))**2
-!
-  ZOMP1(IW+1:IE-2,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW+1:IE-2,:,:))**2
-  ZOMP2(IW+1:IE-2,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW+1:IE-2,:,:))**2
-  ZOMP3(IW+1:IE-2,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW+1:IE-2,:,:))**2
-  ZOMN1(IW+1:IE-2,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW+1:IE-2,:,:))**2
-  ZOMN2(IW+1:IE-2,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW+1:IE-2,:,:))**2
-  ZOMN3(IW+1:IE-2,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW+1:IE-2,:,:))**2
-!
-    PR(IW+1:IE-2,:,:) = (ZOMP2(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ &
-      ZOMP2(IW+1:IE-2,:,:)+ &
-      ZOMP3(IW+1:IE-2,:,:)) * ZFPOS2(IW+1:IE-2,:,:)  +                 &
-      ZOMP1(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ZOMP2(IW+1:IE-2,:,:)+ &
-      ZOMP3(IW+1:IE-2,:,:)) * ZFPOS1(IW+1:IE-2,:,:)  +                 &
-      ZOMP3(IW+1:IE-2,:,:)/(ZOMP1(IW+1:IE-2,:,:)+ZOMP2(IW+1:IE-2,:,:)+ &
-      ZOMP3(IW+1:IE-2,:,:)) * ZFPOS3(IW+1:IE-2,:,:)) *                 &
-      (0.5+SIGN(0.5,PRUCT(IW+1:IE-2,:,:))) +                           &
-      (ZOMN2(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+&
-      ZOMN3(IW+1:IE-2,:,:)) * ZFNEG2(IW+1:IE-2,:,:) +                  &
-      ZOMN1(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+ &
-      ZOMN3(IW+1:IE-2,:,:)) * ZFNEG1(IW+1:IE-2,:,:)   +                &
-      ZOMN3(IW+1:IE-2,:,:)/(ZOMN1(IW+1:IE-2,:,:)+ZOMN2(IW+1:IE-2,:,:)+ &
-      ZOMN3(IW+1:IE-2,:,:)) * ZFNEG3(IW+1:IE-2,:,:)) *                 &
-      (0.5-SIGN(0.5,PRUCT(IW+1:IE-2,:,:)))
-!
-END SELECT
-!
-PR = PR * PRUCT
+!   ! WENO scheme order 3, IE-1
+    ZFPOS1(IE-1,:,:) = 0.5 * (3.0*PSRC(IE-1,:,:) - PSRC(IE-2,:,:)) ! First positive flux
+    ZFPOS2(IE-1,:,:) = 0.5 * ( PSRC(IE-1,:,:) + PSRC(IE,:,:)) ! Second positive flux
+    ZBPOS1(IE-1,:,:) = (PSRC(IE-1,:,:) - PSRC(IE-2,:,:))**2 ! First positive smoothness indicator
+    ZBPOS2(IE-1,:,:) = (PSRC(IE,:,:)   - PSRC(IE-1,:,:))**2 ! Second positive smoothness indicator
+!
+    ZFNEG1(IE-1,:,:) = 0.5 * (3.0*PSRC(IE,:,:)   - PSRC(IE+1,:,:)) ! First negative flux
+    ZFNEG2(IE-1,:,:) = 0.5 * ( PSRC(IE-1,:,:) + PSRC(IE,:,:)) ! Second negative flux
+    ZBNEG1(IE-1,:,:) = (PSRC(IE,:,:)   - PSRC(IE+1,:,:))**2 ! First negative smoothness indicator
+    ZBNEG2(IE-1,:,:) = (PSRC(IE-1,:,:) - PSRC(IE,:,:))**2  ! Second negative smoothness indicator
+!
+    ZOMP1(IE-1,:,:) = 1./3. / (ZEPS + ZBPOS1(IE-1,:,:))**2 ! First positive non-normalized weight
+    ZOMP2(IE-1,:,:) = 2./3. / (ZEPS + ZBPOS2(IE-1,:,:))**2 ! Second positive non-normalized weight
+    ZOMN1(IE-1,:,:) = 1./3. / (ZEPS + ZBNEG1(IE-1,:,:))**2 ! First negative non-normalized weight
+    ZOMN2(IE-1,:,:) = 2./3. / (ZEPS + ZBNEG2(IE-1,:,:))**2 ! Second negative non-normalized weight
+! 
+    PR(IE-1,:,:) = (ZOMN2(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:))*ZFNEG2(IE-1,:,:) + &
+      (ZOMN1(IE-1,:,:)/(ZOMN1(IE-1,:,:)+ZOMN2(IE-1,:,:))*ZFNEG1(IE-1,:,:))) &
+      *(0.5-SIGN(0.5,PRUCT(IE-1,:,:))) + &
+                 (ZOMP2(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:))*ZFPOS2(IE-1,:,:) + &
+                   (ZOMP1(IE-1,:,:)/(ZOMP1(IE-1,:,:)+ZOMP2(IE-1,:,:))*ZFPOS1(IE-1,:,:))) &
+      * (0.5+SIGN(0.5,PRUCT(IE-1,:,:)))  ! Total flux
+! 
+ END SELECT ! SELECT CASE (HLBCX(2)) ! X direction LBC type on right side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! East border is proc border -- IE-1,IE
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >= 3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+! 
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(IE-1,:,:) = 1./6. * (2.0*PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + 11.0*PSRC(IE-1,:,:)) ! Flux IE-1
+ ZFPOS1(IE,:,:)   = 1./6. * (2.0*PSRC(IE-2,:,:) - 7.0*PSRC(IE-1,:,:) + 11.0*PSRC(IE,:,:)) ! Flux IE
+ ZBPOS1(IE-1,:,:) = 13./12. * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) +     PSRC(IE-1,:,:))**2 & 
+        + 1./4    * (PSRC(IE-3,:,:) - 4.0*PSRC(IE-2,:,:) + 3.0*PSRC(IE-1,:,:))**2  ! Smoothness indicator IE-1
+ ZBPOS1(IE,:,:)   = 13./12. * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 & 
+        + 1./4    * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2  ! Smoothness indicator IE
+ ZOMP1(IE-1:IE,:,:)  = 1./10. / (ZEPS + ZBPOS1(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(IE-1,:,:) = 1./6. * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE-1
+ ZFPOS2(IE,:,:)   = 1./6. * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZBPOS2(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + PSRC(IE,:,:))**2 &
+      + 1./4   * (PSRC(IE-2,:,:) -                      PSRC(IE,:,:))**2 ! Smoothness indicator IE-1
+ ZBPOS2(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                   PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZOMP2(IE-1:IE,:,:)  = 3./5. / (ZEPS + ZBPOS2(IE-1:IE,:,:))**2  ! Non-normalized weight IE-1,IE
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE-1,:,:) = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IE+2,:,:)) ! Flux IE
+ ZBPOS3(IE-1,:,:) = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE
+ ZOMP3(IE-1:IE,:,:)  = 3./10. / (ZEPS + ZBPOS3(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(IE-1,:,:) = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IE+2,:,:)) ! Flux IE-1
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IE+2,:,:) + 2.0*PSRC(IE+3,:,:)) ! Flux IE
+ ZBNEG1(IE-1,:,:) = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE-1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2  ! Smoothness indicator IE
+ ZOMN1(IE-1:IE,:,:) = 1./10. / (ZEPS + ZBNEG1(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(IE-1,:,:) = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE-1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IE+2,:,:)) ! Flux IE
+ ZBNEG2(IE-1,:,:)  = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE-1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IE+2,:,:))**2 ! Smoothness indicator IE
+ ZOMN2(IE-1:IE,:,:) = 3./5. / (ZEPS + ZBNEG2(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(IE-1,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE-1
+ ZFNEG3(IE,:,:)   = 1./6 * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZBNEG3(IE-1,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 &
+        + 1./4   * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2 ! Smoothness indicator IE-1
+ ZBNEG3(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IE+1,:,:))**2 &
+        + 1./4   * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZOMN3(IE-1:IE,:,:) = 3./10. / (ZEPS + ZBNEG3(IE-1:IE,:,:))**2 ! Non-normalized weight IE-1,IE
+!
+ ! ----- Total flux -----
+! 
+ PR(IE-1:IE,:,:) = ( ZOMP1(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS1(IE-1:IE,:,:) &
+                       + ZOMP2(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS2(IE-1:IE,:,:) & 
+                       + ZOMP3(IE-1:IE,:,:)/(ZOMP1(IE-1:IE,:,:)+ZOMP2(IE-1:IE,:,:)+ZOMP3(IE-1:IE,:,:)) * ZFPOS3(IE-1:IE,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IE-1:IE,:,:))) &
+                    + ( ZOMN1(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG1(IE-1:IE,:,:) &
+                       + ZOMN2(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG2(IE-1:IE,:,:) &
+                       + ZOMN3(IE-1:IE,:,:)/(ZOMN1(IE-1:IE,:,:)+ZOMN2(IE-1:IE,:,:)+ZOMN3(IE-1:IE,:,:)) * ZFNEG3(IE-1:IE,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IE-1:IE,:,:)))
+! 
+ END IF ! NHALO
+!
+END IF ! IF(LWEST_ll()) 
+!-------------------------------------------------------------------------------
+!
+PR = PR * PRUCT ! Add contravariant flux
 !
 END SUBROUTINE ADVEC_WENO_K_3_UX
 !
 !------------------------------------------------------------------------------
 !
 !     ############################################################
-      SUBROUTINE ADVEC_WENO_K_3_MX(HLBCX,PSRC, PRUCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_MX(HLBCX,PSRC, PRUCT, PR)
 !     ############################################################
 !!
 !!**** Computes PRUCT * PWT (or PRUCT * PVT). Upstream fluxes of W (or V)
@@ -765,13 +776,16 @@ END SUBROUTINE ADVEC_WENO_K_3_UX
 !!
 !!    MODIFICATIONS
 !!    -------------
+!! T. Lunet 02/10/2014:  Correction of periodic boudary conditions
+!!       Change of structure in order to adapt WENO to NHALOK
+!!       Suppression of second layer HALO pointers
+!!       Complete code documentation
 !!
 !------------------------------------------------------------------------------
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 IMPLICIT NONE
 !
@@ -785,7 +799,6 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRUCT ! contrav. comp. on MASS GRID
 ! output source term
 !
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 !*       0.2   Declarations of local variables :
 !
@@ -795,12 +808,10 @@ INTEGER::  IW,IE   ! Coordinate of third order diffusion area
 !
 INTEGER:: ILUOUT,IRESP   ! for prints
 !
-!
 ! intermediate reconstruction fluxes for positive wind case
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -813,14 +824,8 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMN1, ZOMN2, ZOMN3
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
+! EPSILON for weno weights calculation
+! 
 REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !-------------------------------------------------------------------------------
@@ -856,524 +861,560 @@ ZOMN1  = 0.0
 ZOMN2  = 0.0
 ZOMN3  = 0.0 
 !
-!------------------------------------------------------------------------------
-!
-SELECT CASE ( HLBCX(1) ) ! X direction LBC type: (1) for left side
+!-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
+IW=IIB
+IE=IIE
 !
-!*       1.1    CYCLIC CASE IN THE X DIRECTION:
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IW+2 -> IE-1
+! Computation at the mass point on Ugrid u(i-1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-CASE ('CYCL')          ! In that case one must have HLBCX(1) == HLBCX(2)
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-3, i-2, i-1
+ZFPOS1(IW+2:IE-1,:,:) = 1./6.   * (2.0*PSRC(IW-1:IE-4,:,:) - 7.0*PSRC(IW:IE-3,:,:) + 11.0*PSRC(IW+1:IE-2,:,:))   ! Flux
+ZBPOS1(IW+2:IE-1,:,:) = 13./12. * (    PSRC(IW-1:IE-4,:,:) - 2.0*PSRC(IW:IE-3,:,:) +      PSRC(IW+1:IE-2,:,:))**2 & 
+      + 1./4    * (    PSRC(IW-1:IE-4,:,:) - 4.0*PSRC(IW:IE-3,:,:) + 3.0* PSRC(IW+1:IE-2,:,:))**2  ! Smoothness indicator
+ZOMP1(IW+2:IE-1,:,:)  = 1./10. /  (ZEPS + ZBPOS1(IW+2:IE-1,:,:))**2             ! Non-normalized weight
+!
+! Second positive stencil, needs indices i-2, i-1, i
+ZFPOS2(IW+2:IE-1,:,:) = 1./6.  * (-1.0*PSRC(IW:IE-3,:,:) + 5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))  ! Flux
+ZBPOS2(IW+2:IE-1,:,:) = 13./12 * (     PSRC(IW:IE-3,:,:) - 2.0*PSRC(IW+1:IE-2,:,:) +     PSRC(IW+2:IE-1,:,:))**2 &
+      + 1./4   * (     PSRC(IW:IE-3,:,:) -                               PSRC(IW+2:IE-1,:,:))**2 ! Smoothness indicator
+ZOMP2(IW+2:IE-1,:,:)  = 3./5. /  (ZEPS + ZBPOS2(IW+2:IE-1,:,:))**2             ! Non-normalized weight
+!
+! Third positive stencil, needs indices i-1, i, i+1
+ZFPOS3(IW+2:IE-1,:,:) = 1./6   * (2.0*PSRC(IW+1:IE-2,:,:) + 5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,:,:))  ! Flux
+ZBPOS3(IW+2:IE-1,:,:) = 13./12 * ( PSRC(IW+1:IE-2,:,:) - 2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW+1:IE-2,:,:) - 4.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 ! Smoothness indicator
+ZOMP3(IW+2:IE-1,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW+2:IE-1,:,:))**2           ! Non-normalized weight
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i, i+1, i+2
+ZFNEG1(IW+2:IE-1,:,:) = 1./6.   * (11.0*PSRC(IW+2:IE-1,:,:) - 7.0*PSRC(IW+3:IE,:,:) + 2.0*PSRC(IW+4:IE+1,:,:))   ! Flux
+ZBNEG1(IW+2:IE-1,:,:) = 13./12. * (     PSRC(IW+2:IE-1,:,:) - 2.0*PSRC(IW+3:IE,:,:) +     PSRC(IW+4:IE+1,:,:))**2 & 
+      + 1./4    * (3.0* PSRC(IW+2:IE-1,:,:) - 4.0*PSRC(IW+3:IE,:,:) +     PSRC(IW+4:IE+1,:,:))**2  ! Smoothness indicator
+ZOMN1(IW+2:IE-1,:,:)  = 1./10. /  (ZEPS + ZBNEG1(IW+2:IE-1,:,:))**2             ! Non-normalized weight
+!
+! Second negative stencil, needs indices i-1, i, i+1
+ZFNEG2(IW+2:IE-1,:,:) = 1./6.  * (2.0*PSRC(IW+1:IE-2,:,:) + 5.0*PSRC(IW+2:IE-1,:,:) - 1.0*PSRC(IW+3:IE,:,:))  ! Flux
+ZBNEG2(IW+2:IE-1,:,:) = 13./12 * (    PSRC(IW+1:IE-2,:,:) - 2.0*PSRC(IW+2:IE-1,:,:) +     PSRC(IW+3:IE,:,:))**2 &
+      + 1./4   * (    PSRC(IW+1:IE-2,:,:) -                               PSRC(IW+3:IE,:,:))**2 ! Smoothness indicator
+ZOMN2(IW+2:IE-1,:,:)  = 3./5. /  (ZEPS + ZBNEG2(IW+2:IE-1,:,:))**2            ! Non-normalized weight
+!
+! Third negative stencil, needs indices i-2, i-1, i
+ZFNEG3(IW+2:IE-1,:,:) = 1./6   * (-1.0*PSRC(IW:IE-3,:,:) + 5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))  ! Flux
+ZBNEG3(IW+2:IE-1,:,:) = 13./12 * (  PSRC(IW:IE-3,:,:) - 2.0*PSRC(IW+1:IE-2,:,:) +     PSRC(IW+2:IE-1,:,:))**2 &
+      + 1./4   * (     PSRC(IW:IE-3,:,:) - 4.0*PSRC(IW+1:IE-2,:,:) + 3.0*PSRC(IW+2:IE-1,:,:))**2 ! Smoothness indicator
+ZOMN3(IW+2:IE-1,:,:)  = 3./10. / (ZEPS + ZBNEG3(IW+2:IE-1,:,:))**2             ! Non-normalized weight
+!
+!
+! ----- Total flux -----
+!
+PR(IW+2:IE-1,:,:) = (ZOMP1(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+ZOMP2(IW+2:IE-1,:,:)+ZOMP3(IW+2:IE-1,:,:)) &
+           * ZFPOS1(IW+2:IE-1,:,:) + &
+                      ZOMP2(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+ZOMP2(IW+2:IE-1,:,:)+ZOMP3(IW+2:IE-1,:,:)) &
+           * ZFPOS2(IW+2:IE-1,:,:) + & 
+                      ZOMP3(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+ZOMP2(IW+2:IE-1,:,:)+ZOMP3(IW+2:IE-1,:,:)) &
+           * ZFPOS3(IW+2:IE-1,:,:)) &
+                    * (0.5+SIGN(0.5,PRUCT(IW+2:IE-1,:,:))) &
+                  + (ZOMN1(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+ZOMN3(IW+2:IE-1,:,:)) &
+           * ZFNEG1(IW+2:IE-1,:,:)  &
+                     + ZOMN2(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+ZOMN3(IW+2:IE-1,:,:)) &
+           * ZFNEG2(IW+2:IE-1,:,:)  &
+                     + ZOMN3(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+ZOMN3(IW+2:IE-1,:,:)) &
+           * ZFNEG3(IW+2:IE-1,:,:))  & 
+                    * (0.5-SIGN(0.5,PRUCT(IW+2:IE-1,:,:)))
 !
-  IF(NHALO == 1) THEN
-    IW=IIB
-    IE=IIE
-  ELSE
-    CALL FMLOOK_ll(CLUOUT0,CLUOUT0,ILUOUT,IRESP)
-    WRITE(ILUOUT,*) 'ERROR : 3rd order advection in CYCLic case '
-    WRITE(ILUOUT,*) 'cannot be used with NHALO=2'
-    CALL ABORT
-    STOP
-  END IF  
+!-------------------------------------------------------------------------------
+!*       1.2.   West border
+!               ---------------------
 !
-! r: many left cells in regard to 'i-1' cell for each stencil
+IF( LWEST_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! West border is physical -- IW+1,IW
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCX(1)) ! X direction LBC type on left side
 ! 
-! intermediate fluxes at the mass point on Ugrid u(i-1/2,j,k)=((i-1)+1/2,j,k) 
-! for positive wind case (left to the right)
-! (r=2 for the first stencil ZFPOS1, r=1 for the second ZFPOS2 and
-!  r=0 for the last ZFPOS3)
-!
-  ZFPOS1(IW+2:IE,:,:) = 1./6 * (2.0*PSRC(IW-1:IE-3,:,:) - 7.0*PSRC(IW:IE-2,:,:) + &
-                        11.0*PSRC(IW+1:IE-1,:,:))
-  ZFPOS1(IW+1,   :,:) = 1./6 * (2.0*TPHALO2%WEST(:,:)   - 7.0*PSRC(IW-1,   :,:) + &
-                        11.0*PSRC(IW,       :,:))
-  ZFPOS1(IE+1,:,:) = 0.5 * (3.0*PSRC(IE,  :,:) - PSRC(IE-1,:,:))
-  ZFPOS1(IW,  :,:) = 0.5 * (3.0*PSRC(IW-1,:,:) - TPHALO2%WEST(:,:) )
-  ZFPOS1(IW-1,:,:) = - 999.
-!
-!
-  ZFPOS2(IW+1:IE,:,:) = 1./6 * (-1.0*PSRC(IW-1:IE-2,:,:) + 5.0*PSRC(IW:IE-1,:,:) + &
-                        2.0*PSRC(IW+1:IE,:,:))
-  ZFPOS2(IE+1,:,:) = 0.5 * (PSRC(IE+1,:,:)    + PSRC(IE,  :,:)) 
-  ZFPOS2(IW,  :,:) = 0.5 * (PSRC(IW-1,:,:)    + PSRC(IW,  :,:))
-  ZFPOS2(IW-1,:,:) = 0.5 * (TPHALO2%WEST(:,:) + PSRC(IW-1,:,:))
-!
-!
-  ZFPOS3(IW+1:IE,:,:) = 1./6 * (2.0*PSRC(IW:IE-1,:,:) + 5.0*PSRC(IW+1:IE,:,:) - &
-                        PSRC(IW+2:IE+1,:,:))
-!
-! r: many left cells in regard to 'i' cell for each stencil
-!
-! intermediate fluxes at the mass point on Ugrid u(i-1/2,j,k) for negative wind
-! case (R. to the L.)
-! (r=2 for the third stencil ZFNEG3=ZFPOS2, r=1 for the second ZFNEG2=ZFPOS3 
-!  and r=0 for the first ZFNEG1)
-!
-  ZFNEG1(IW+1:IE-1,:,:) = 1./6 * (11.0*PSRC(IW+1:IE-1,:,:) - 7.0*PSRC(IW+2:IE,:,:)&
-                          + 2.0*PSRC(IW+3:IE+1,:,:))
-  ZFNEG1(IE,       :,:) = 1./6 * (11.0*PSRC(IE,       :,:) - 7.0*PSRC(IE+1,   :,:)&
-                          + 2.0*TPHALO2%EAST(:,:))
-  ZFNEG1(IW,  :,:) = 0.5 * (3.0*PSRC(IW,  :,:) - PSRC(IW+1,   :,:))
-  ZFNEG1(IW-1,:,:) = 0.5 * (3.0*PSRC(IW-1,:,:) - PSRC(IW,     :,:))
-  ZFNEG1(IE+1,:,:) = 0.5 * (3.0*PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))
-!
-!
-  ZFNEG2(IW+1:IE,:,:) = 1./6 * (2.0*PSRC(IW:IE-1,:,:) + 5.0*PSRC(IW+1:IE,:,:) - &
-                        PSRC(IW+2:IE+1,:,:))
-  ZFNEG2(IW,  :,:) = 0.5 * (PSRC(IW,  :,:) + PSRC(IW-1,   :,:))
-  ZFNEG2(IW-1,:,:) = 0.5 * (PSRC(IW-1,:,:) + TPHALO2%WEST(:,:))
-  ZFNEG2(IE+1,:,:) = 0.5 * (PSRC(IE+1,:,:) + PSRC(IE,     :,:))
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
+!
+ IF(LEAST_ll()  .AND. .FALSE. ) THEN  ! East border is physical
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(IW+1,:,:) = 1./6. * (2.0*PSRC(IE,:,:)   - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:)) ! Flux IW+1
+ ZFPOS1(IW,:,:)   = 1./6. * (2.0*PSRC(IE-1,:,:) - 7.0*PSRC(IE,:,:)   + 11.0*PSRC(IW-1,:,:)) ! Flux IW
+ ZBPOS1(IW+1,:,:) = 13./12. * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+        + 1./4    * (PSRC(IE,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2   ! Smoothness indicator IW+1
+ ZBPOS1(IW,:,:) = 13./12. * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IW-1,:,:))**2 & 
+      + 1./4    * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IW-1,:,:))**2  ! Smoothness indicator IW
+ ZOMP1(IW:IW+1,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(IW+1,:,:) = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IE,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBPOS2(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IW,:,:))**2  ! Smoothness indicator IW
+ ZOMP2(IW:IW+1,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW:IW+1,:,:))**2  ! Non-normalized weight IW+1,IW
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(IW+1,:,:) = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IE,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBNEG3(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+        + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+        + 1./4   * (PSRC(IE,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW
+ ZOMN3(IW:IW+1,:,:) = 3./10. / (ZEPS + ZBNEG3(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ELSEIF(IW>3) THEN ! East boundary is proc border, with minimum 3 HALO points on west side
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(IW+1,:,:) = 1./6. * (2.0*PSRC(IW-2,:,:)   - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:)) ! Flux IW+1
+ ZFPOS1(IW,:,:)   = 1./6. * (2.0*PSRC(IW-3,:,:) - 7.0*PSRC(IW-2,:,:)   + 11.0*PSRC(IW-1,:,:)) ! Flux IW
+ ZBPOS1(IW+1,:,:) = 13./12. * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+        + 1./4    * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2   ! Smoothness indicator IW+1
+ ZBPOS1(IW,:,:) = 13./12. * (PSRC(IW-3,:,:) - 2.0*PSRC(IW-2,:,:) +     PSRC(IW-1,:,:))**2 & 
+      + 1./4    * (PSRC(IW-3,:,:) - 4.0*PSRC(IW-2,:,:) + 3.0*PSRC(IW-1,:,:))**2  ! Smoothness indicator IW
+ ZOMP1(IW:IW+1,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(IW+1,:,:) = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBPOS2(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IW-2,:,:) -                      PSRC(IW,:,:))**2  ! Smoothness indicator IW
+ ZOMP2(IW:IW+1,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW:IW+1,:,:))**2  ! Non-normalized weight IW+1,IW
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(IW+1,:,:) = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBNEG3(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+        + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+        + 1./4   * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW
+ ZOMN3(IW:IW+1,:,:) = 3./10. / (ZEPS + ZBNEG3(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ELSE ! East boundary is proc border, with NHALO < 3 on west side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on west side'
+  CALL ABORT
+ ENDIF
 ! 
+ ! Third positive stencil, needs indices i-1, i, i+1
+ ZFPOS3(IW+1,:,:) = 1./6 * (2.0*PSRC(IW,:,:) + 5.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! Flux IW+1
+ ZFPOS3(IW,:,:)   = 1./6 * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:) - PSRC(IW+1,:,:)) ! Flux IW
+ ZBPOS3(IW+1,:,:) = 13./12 * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 ! Smoothness indicator IW+1
+ ZBPOS3(IW,:,:)  = 13./12 * (    PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZOMP3(IW:IW+1,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(IW+1,:,:) = 1./6. * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + 2.0*PSRC(IW+3,:,:)) ! Flux IW+1
+ ZFNEG1(IW,:,:)   = 1./6. * (11.0*PSRC(IW,:,:)   - 7.0*PSRC(IW+1,:,:) + 2.0*PSRC(IW+2,:,:)) ! Flux IW
+ ZBNEG1(IW+1,:,:) = 13./12. * (    PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2  ! Smoothness indicator IW+1
+ ZBNEG1(IW,:,:)   = 13./12. * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2  ! Smoothness indicator IW
+ ZOMN1(IW:IW+1,:,:) = 1./10. / (ZEPS + ZBNEG1(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(IW+1,:,:) = 1./6. * (2.0*PSRC(IW,:,:)   + 5.0*PSRC(IW+1,:,:) - 1.0*PSRC(IW+2,:,:)) ! Flux IW+1
+ ZFNEG2(IW,:,:)   = 1./6. * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   - 1.0*PSRC(IW+1,:,:)) ! Flux IW
+ ZBNEG2(IW+1,:,:) = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (PSRC(IW,:,:) -                      PSRC(IW+2,:,:))**2 ! Smoothness indicator IW+1
+ ZBNEG2(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZOMN2(IW:IW+1,:,:) = 3./5. / (ZEPS + ZBNEG2(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! ----- Total flux -----
+! 
+ PR(IW:IW+1,:,:) = ( ZOMP1(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS1(IW:IW+1,:,:) &
+                       + ZOMP2(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS2(IW:IW+1,:,:) & 
+                       + ZOMP3(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS3(IW:IW+1,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IW:IW+1,:,:))) &
+                    + ( ZOMN1(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG1(IW:IW+1,:,:) &
+                       + ZOMN2(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG2(IW:IW+1,:,:) &
+                       + ZOMN3(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG3(IW:IW+1,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IW:IW+1,:,:)))
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IW
+    PR(IW,:,:) = PSRC(IW-1,:,:) * (0.5+SIGN(0.5,PRUCT(IW,:,:))) + &
+                 PSRC(IW,:,:)  * (0.5-SIGN(0.5,PRUCT(IW,:,:)))
+!
+!   ! WENO scheme order 3, IW+1
+    ZFPOS1(IW+1,:,:) = 0.5 * (3.0*PSRC(IW,:,:) - PSRC(IW-1,:,:)) ! First positive flux
+    ZFPOS2(IW+1,:,:) = 0.5 * ( PSRC(IW,:,:) + PSRC(IW+1,:,:)) ! Second positive flux
+    ZBPOS1(IW+1,:,:) = (PSRC(IW,:,:)   - PSRC(IW-1,:,:))**2 ! First positive smoothness indicator
+    ZBPOS2(IW+1,:,:) = (PSRC(IW+1,:,:) - PSRC(IW,:,:))**2  ! Second positive smoothness indicator
+!
+    ZFNEG1(IW+1,:,:) = 0.5 * (3.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! First negative flux
+    ZFNEG2(IW+1,:,:) = 0.5 * ( PSRC(IW,:,:)   + PSRC(IW+1,:,:)) ! Second negative flux
+    ZBNEG1(IW+1,:,:) = (PSRC(IW+1,:,:) - PSRC(IW+2,:,:))**2 ! First negative smoothness indicator
+    ZBNEG2(IW+1,:,:) = (PSRC(IW,:,:)   - PSRC(IW+1,:,:))**2 ! Second negative smoothness indicator
+!
+    ZOMP1(IW+1,:,:) = 1./3. / (ZEPS + ZBPOS1(IW+1,:,:))**2 ! First positive non-normalized weight
+    ZOMP2(IW+1,:,:) = 2./3. / (ZEPS + ZBPOS2(IW+1,:,:))**2 ! Second positive non-normalized weight
+    ZOMN1(IW+1,:,:) = 1./3. / (ZEPS + ZBNEG1(IW+1,:,:))**2 ! First negative non-normalized weight
+    ZOMN2(IW+1,:,:) = 2./3. / (ZEPS + ZBNEG2(IW+1,:,:))**2 ! Second negative non-normalized weight
+! 
+    PR(IW+1,:,:) = (ZOMN2(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)) * ZFNEG2(IW+1,:,:) + &
+            (ZOMN1(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)) * ZFNEG1(IW+1,:,:))) &
+          *(0.5-SIGN(0.5,PRUCT(IW+1,:,:))) + &
+      (ZOMP2(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)) * ZFPOS2(IW+1,:,:) + &
+      (ZOMP1(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)) * ZFPOS1(IW+1,:,:))) &
+      *(0.5+SIGN(0.5,PRUCT(IW+1,:,:)))  ! Total flux
+!
+ END SELECT ! SELECT CASE (HLBCX(1)) ! X direction LBC type on left side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! West border is proc border -- IW,IW-1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+!
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(IW+1,:,:) = 1./6. * (2.0*PSRC(IW-2,:,:)   - 7.0*PSRC(IW-1,:,:) + 11.0*PSRC(IW,:,:)) ! Flux IW+1
+ ZFPOS1(IW,:,:)   = 1./6. * (2.0*PSRC(IW-3,:,:) - 7.0*PSRC(IW-2,:,:)   + 11.0*PSRC(IW-1,:,:)) ! Flux IW
+ ZBPOS1(IW+1,:,:) = 13./12. * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 & 
+        + 1./4    * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2   ! Smoothness indicator IW+1
+ ZBPOS1(IW,:,:) = 13./12. * (PSRC(IW-3,:,:) - 2.0*PSRC(IW-2,:,:) +     PSRC(IW-1,:,:))**2 & 
+      + 1./4    * (PSRC(IW-3,:,:) - 4.0*PSRC(IW-2,:,:) + 3.0*PSRC(IW-1,:,:))**2  ! Smoothness indicator IW
+ ZOMP1(IW:IW+1,:,:)  = 1./10. / (ZEPS + ZBPOS1(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(IW+1,:,:) = 1./6.* (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFPOS2(IW,:,:)   = 1./6.* (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBPOS2(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBPOS2(IW,:,:)   = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IW-2,:,:) -                      PSRC(IW,:,:))**2  ! Smoothness indicator IW
+ ZOMP2(IW:IW+1,:,:)  = 3./5. / (ZEPS + ZBPOS2(IW:IW+1,:,:))**2  ! Non-normalized weight IW+1,IW
+! 
+ ! Third positive stencil, needs indices i-1, i, i+1
+ ZFPOS3(IW+1,:,:) = 1./6 * (2.0*PSRC(IW,:,:) + 5.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:)) ! Flux IW+1
+ ZFPOS3(IW,:,:)   = 1./6 * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:) - PSRC(IW+1,:,:)) ! Flux IW
+ ZBPOS3(IW+1,:,:) = 13./12 * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 ! Smoothness indicator IW+1
+ ZBPOS3(IW,:,:)  = 13./12 * (    PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZOMP3(IW:IW+1,:,:)  = 3./10. / (ZEPS + ZBPOS3(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(IW+1,:,:) = 1./6. * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + 2.0*PSRC(IW+3,:,:)) ! Flux IW+1
+ ZFNEG1(IW,:,:)   = 1./6. * (11.0*PSRC(IW,:,:)   - 7.0*PSRC(IW+1,:,:) + 2.0*PSRC(IW+2,:,:)) ! Flux IW
+ ZBNEG1(IW+1,:,:) = 13./12. * (    PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) + PSRC(IW+3,:,:))**2  ! Smoothness indicator IW+1
+ ZBNEG1(IW,:,:)   = 13./12. * (    PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2  ! Smoothness indicator IW
+ ZOMN1(IW:IW+1,:,:) = 1./10. / (ZEPS + ZBNEG1(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(IW+1,:,:) = 1./6. * (2.0*PSRC(IW,:,:)   + 5.0*PSRC(IW+1,:,:) - 1.0*PSRC(IW+2,:,:)) ! Flux IW+1
+ ZFNEG2(IW,:,:)   = 1./6. * (2.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   - 1.0*PSRC(IW+1,:,:)) ! Flux IW
+ ZBNEG2(IW+1,:,:) = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) + PSRC(IW+2,:,:))**2 &
+      + 1./4   * (PSRC(IW,:,:) -                      PSRC(IW+2,:,:))**2 ! Smoothness indicator IW+1
+ ZBNEG2(IW,:,:)   = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 &
+      + 1./4   * (PSRC(IW-1,:,:) -                    PSRC(IW+1,:,:))**2 ! Smoothness indicator IW
+ ZOMN2(IW:IW+1,:,:) = 3./5. / (ZEPS + ZBNEG2(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(IW+1,:,:) = 1./6 * (-1.0*PSRC(IW-1,:,:) + 5.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IW+1
+ ZFNEG3(IW,:,:)   = 1./6 * (-1.0*PSRC(IW-2,:,:)   + 5.0*PSRC(IW-1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IW
+ ZBNEG3(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +     PSRC(IW+1,:,:))**2 &
+        + 1./4   * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) + 3.0*PSRC(IW+1,:,:))**2 ! Smoothness indicator IW+1
+ ZBNEG3(IW,:,:)   = 13./12 * (PSRC(IW-2,:,:) - 2.0*PSRC(IW-1,:,:) +     PSRC(IW,:,:))**2 &
+        + 1./4   * (PSRC(IW-2,:,:) - 4.0*PSRC(IW-1,:,:) + 3.0*PSRC(IW,:,:))**2 ! Smoothness indicator IW
+ ZOMN3(IW:IW+1,:,:) = 3./10. / (ZEPS + ZBNEG3(IW:IW+1,:,:))**2 ! Non-normalized weight IW+1,IW
+!
+ ! ----- Total flux -----
+! 
+ PR(IW:IW+1,:,:) = ( ZOMP1(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS1(IW:IW+1,:,:) &
+                       + ZOMP2(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS2(IW:IW+1,:,:) & 
+                       + ZOMP3(IW:IW+1,:,:)/(ZOMP1(IW:IW+1,:,:)+ZOMP2(IW:IW+1,:,:)+ZOMP3(IW:IW+1,:,:)) * ZFPOS3(IW:IW+1,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IW:IW+1,:,:))) &
+                    + ( ZOMN1(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG1(IW:IW+1,:,:) &
+                       + ZOMN2(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG2(IW:IW+1,:,:) &
+                       + ZOMN3(IW:IW+1,:,:)/(ZOMN1(IW:IW+1,:,:)+ZOMN2(IW:IW+1,:,:)+ZOMN3(IW:IW+1,:,:)) * ZFNEG3(IW:IW+1,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IW:IW+1,:,:)))
 !
-  ZFNEG3(IW+1:IE,:,:) = 1./6 * (-1.0*PSRC(IW-1:IE-2,:,:) + 5.0*PSRC(IW:IE-1,:,:) + &
-                        2.0*PSRC(IW+1:IE,:,:))
-!
-! smoothness indicators for positive wind case
+ END IF ! NHALO
 !
-  ZBPOS1(IW+2:IE,:,:) = 13./12 * (PSRC(IW-1:IE-3,:,:) - 2.0*PSRC(IW:IE-2,:,:) + &
-                        PSRC(IW+1:IE-1,:,:))**2 + &
-                        1./4 * (PSRC(IW-1:IE-3,:,:) - 4.0*PSRC(IW:IE-2,:,:) + &
-                        3.0*PSRC(IW+1:IE-1,:,:))**2
-  ZBPOS1(IW+1,   :,:) = 13./12 * (TPHALO2%WEST(:,:) - 2.0*PSRC(IW-1,:,:) + &
-                        PSRC(IW,:,:))**2 + &
-                        1./4 * (TPHALO2%WEST(:,:) - 4.0*PSRC(IW-1,:,:) + &
-                        3.0*PSRC(IW,:,:))**2
-  ZBPOS1(IE+1,:,:) = (PSRC(IE,  :,:) - PSRC(IE-1,:,:))**2
-  ZBPOS1(IW,  :,:) = (PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))**2
-  ZBPOS1(IW-1,:,:) = - 999.
-!
-!
-  ZBPOS2(IW+1:IE,:,:) = 13./12 * (PSRC(IW-1:IE-2,:,:) - 2.0*PSRC(IW:IE-1,:,:) + &
-                        PSRC(IW+1:IE,:,:))**2 + &
-                        1./4 * (PSRC(IW-1:IE-2,:,:) - PSRC(IW+1:IE,:,:))**2
-  ZBPOS2(IE+1,:,:) = (PSRC(IE+1,:,:) - PSRC(IE,:,:))**2
-  ZBPOS2(IW,  :,:) = (PSRC(IW,  :,:) - PSRC(IW-1,:,:))**2
-  ZBPOS2(IW-1,:,:) = (PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))**2
-!
-!
-  ZBPOS3(IW+1:IE,:,:) = 13./12 * (PSRC(IW:IE-1,:,:) - 2.0*PSRC(IW+1:IE,:,:) + &
-                        PSRC(IW+2:IE+1,:,:))**2 + &
-                        1./4 * ( 3.0*PSRC(IW:IE-1,:,:) - 4.0*PSRC(IW+1:IE,:,:) + &
-                        PSRC(IW+2:IE+1,:,:))**2
-!
-! smoothness indicators for negative wind case
-!       
-  ZBNEG1(IW+1:IE-1,:,:) = 13./12 * (PSRC(IW+1:IE-1,:,:) - 2.0*PSRC(IW+2:IE,:,:) + &
-                          PSRC(IW+3:IE+1,:,:))**2 + &
-                          1./4 * ( 3.0*PSRC(IW+1:IE-1,:,:) - 4.0*PSRC(IW+2:IE,:,:)&
-                          + PSRC(IW+3:IE+1,:,:))**2
-  ZBNEG1(IE,       :,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + &
-                          TPHALO2%EAST(:,:))**2 + &
-                          1./4 * ( 3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + &
-                          TPHALO2%EAST(:,:))**2
-  ZBNEG1(IW,  :,:) = (PSRC(IW,  :,:) - PSRC(IW+1,:,:))**2
-  ZBNEG1(IW-1,:,:) = (PSRC(IW-1,:,:) - PSRC(IW,  :,:))**2
-  ZBNEG1(IE+1,:,:) = (PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))**2
-!
-!
-  ZBNEG2(IW+1:IE,:,:) = 13./12 * (PSRC(IW:IE-1,:,:) - 2.0*PSRC(IW+1:IE,:,:) + &
-                        PSRC(IW+2:IE+1,:,:))**2 + &
-                        1./4 * (PSRC(IW:IE-1,:,:) - PSRC(IW+2:IE+1,:,:))**2
-  ZBNEG2(IW,  :,:) = (PSRC(IW-1,:,:) - PSRC(IW,  :,:))**2
-  ZBNEG2(IE+1,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,:,:))**2
-  ZBNEG2(IW-1,:,:) = (TPHALO2%WEST(:,:) - PSRC(IW-1,:,:))**2
-!
-!
-  ZBNEG3(IW+1:IE,:,:) = 13./12 * (PSRC(IW-1:IE-2,:,:) - 2.0*PSRC(IW:IE-1,:,:) + &
-                        PSRC(IW+1:IE,:,:))**2 + &
-                        1./4 * ( PSRC(IW-1:IE-2,:,:) - 4.0*PSRC(IW:IE-1,:,:) + &
-                        3.0*PSRC(IW+1:IE,:,:))**2
+END IF ! IF(LWEST_ll()) 
 !
-! WENO weights
+!-------------------------------------------------------------------------------
+!*       1.3.   East border
+!               ---------------------
 !
-  ZOMP1(IW+1:IE,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW+1:IE,:,:))**2
-  ZOMP2(IW+1:IE,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW+1:IE,:,:))**2
-  ZOMP3(IW+1:IE,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW+1:IE,:,:))**2
-  ZOMN1(IW+1:IE,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW+1:IE,:,:))**2
-  ZOMN2(IW+1:IE,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW+1:IE,:,:))**2
-  ZOMN3(IW+1:IE,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW+1:IE,:,:))**2
-!
-  ZOMP1(IW,  :,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW,  :,:))**2
-  ZOMP2(IW,  :,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW,  :,:))**2
-  ZOMN1(IW,  :,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW,  :,:))**2
-  ZOMN2(IW,  :,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW,  :,:))**2
-  ZOMP1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW-1,:,:))**2
-  ZOMP2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW-1,:,:))**2
-  ZOMN1(IW-1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW-1,:,:))**2
-  ZOMN2(IW-1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW-1,:,:))**2
-  ZOMP1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE+1,:,:))**2
-  ZOMP2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE+1,:,:))**2
-  ZOMN1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE+1,:,:))**2
-  ZOMN2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE+1,:,:))**2 
-!
-! WENO fluxes (5th order)
-!
-  PR(IW+1:IE,:,:) = (ZOMP2(IW+1:IE,:,:)/(ZOMP1(IW+1:IE,:,:)+ZOMP2(IW+1:IE,:,:)+&
-                    ZOMP3(IW+1:IE,:,:)) * ZFPOS2(IW+1:IE,:,:) +                &
-                    ZOMP1(IW+1:IE,:,:)/(ZOMP1(IW+1:IE,:,:)+ZOMP2(IW+1:IE,:,:) +&
-                    ZOMP3(IW+1:IE,:,:)) * ZFPOS1(IW+1:IE,:,:) +                &
-                    ZOMP3(IW+1:IE,:,:)/(ZOMP1(IW+1:IE,:,:)+ZOMP2(IW+1:IE,:,:)+ &
-                    ZOMP3(IW+1:IE,:,:)) *                                      &
-                    ZFPOS3(IW+1:IE,:,:)) * (0.5+SIGN(0.5,PRUCT(IW+1:IE,:,:)))  &
-                  + (ZOMN2(IW+1:IE,:,:)/(ZOMN1(IW+1:IE,:,:)+ZOMN2(IW+1:IE,:,:)+&
-                     ZOMN3(IW+1:IE,:,:)) *                                     &
-                     ZFNEG2(IW+1:IE,:,:)                                       &
-                   + ZOMN1(IW+1:IE,:,:)/(ZOMN1(IW+1:IE,:,:)+ZOMN2(IW+1:IE,:,:)+&
-                     ZOMN3(IW+1:IE,:,:)) * ZFNEG1(IW+1:IE,:,:)                 &
-                   + ZOMN3(IW+1:IE,:,:)/(ZOMN1(IW+1:IE,:,:)+ZOMN2(IW+1:IE,:,:)+&
-                     ZOMN3(IW+1:IE,:,:)) * ZFNEG3(IW+1:IE,:,:))                &
-                   * (0.5-SIGN(0.5,PRUCT(IW+1:IE,:,:)))
-!
-! WENO fluxes (3rd order)
-!
-  PR(IW,:,:) = (ZOMP2(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS2(IW,:,:)    &
-              + ZOMP1(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS1(IW,:,:)) * &
-              (0.5+SIGN(0.5,PRUCT(IW,:,:)))                                     &
-             + (ZOMN2(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG2(IW,:,:)    &
-              + ZOMN1(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG1(IW,:,:)) * &
-              (0.5-SIGN(0.5,PRUCT(IW,:,:)))
-!
-  PR(IW-1,:,:) = (ZOMP2(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) *        &
-     ZFPOS2(IW-1,:,:)                                                        &
-     + ZOMP1(IW-1,:,:)/(ZOMP1(IW-1,:,:)+ZOMP2(IW-1,:,:)) * ZFPOS1(IW-1,:,:)) &
-     * (0.5+SIGN(0.5,PRUCT(IW-1,:,:)))                                       &
-     + (ZOMN2(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) * ZFNEG2(IW-1,:,:) &
-     + ZOMN1(IW-1,:,:)/(ZOMN1(IW-1,:,:)+ZOMN2(IW-1,:,:)) * ZFNEG1(IW-1,:,:)) &
-     * (0.5-SIGN(0.5,PRUCT(IW-1,:,:)))
-!
-  PR(IE+1,:,:) = (ZOMP2(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) *        &
-     ZFPOS2(IE+1,:,:) +                                                      &
-     ZOMP1(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) * ZFPOS1(IE+1,:,:))   &
-     * (0.5+SIGN(0.5,PRUCT(IE+1,:,:)))                                       &
-     + (ZOMN2(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) * ZFNEG2(IE+1,:,:)+&
-     ZOMN1(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) * ZFNEG1(IE+1,:,:))   &
-     * (0.5-SIGN(0.5,PRUCT(IE+1,:,:)))
-!
-!
-!       OPEN, WALL, NEST CASE IN THE X DIRECTION
-!
-CASE ('OPEN','WALL','NEST')
-!
-  IW=IIB
-  IE=IIE
-!
-!  LATERAL BOUNDARY CONDITIONS
-!  AT THE PHYSICAL BORDER: USE A FIRST ORDER UPSTREAM WENO SCHEME AT THE POINTS: IW, IE+1 /AND/ A THIRD ORDER WENO SCHEME AT THE POINTS: IW+1, IE
-!  AT THE PROC. BORDER: A THIRD ORDER UPSTREAM WENO SCHEME AT THE POINTS: IW, IE+1  /AND/ A FIFTH ORDER WENO SCHEME AT THE POINTS: IW+1, IE
-!
-!
-!   PHYSICAL BORDER (WEST)
-!
-  IF(LWEST_ll()) THEN
-!
-!   FIRST ORDER UPSTREAM WENO SCHEME
+IF(LEAST_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! East border is physical -- IE,IE+1
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCX(2)) ! X direction LBC type on right side
+! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
 !
-    PR(IW,:,:) = PSRC(IW-1,:,:) * (0.5+SIGN(0.5,PRUCT(IW,:,:))) + &
-                 PSRC(IW,:,:) * (0.5-SIGN(0.5,PRUCT(IW,:,:)))
-!
-!   THIRD ORDER UPSTREAM WENO SCHEME
-!
-    ZFPOS1(IW+1,:,:) = 0.5 * (3.0*PSRC(IW,:,:) - PSRC(IW-1,:,:))
-    ZFPOS2(IW+1,:,:) = 0.5 * (PSRC(IW,    :,:) + PSRC(IW+1,:,:))
-    ZBPOS1(IW+1,:,:) = (PSRC(IW,  :,:) - PSRC(IW-1,:,:))**2
-    ZBPOS2(IW+1,:,:) = (PSRC(IW+1,:,:) - PSRC(IW,  :,:))**2
-!
-    ZFNEG1(IW+1,:,:) = 0.5 * (3.0*PSRC(IW+1,:,:) - PSRC(IW+2,:,:))
-    ZFNEG2(IW+1,:,:) = 0.5 * (PSRC(IW+1,    :,:) + PSRC(IW,  :,:))
-    ZBNEG1(IW+1,:,:) = (PSRC(IW+1,:,:) - PSRC(IW+2,:,:))**2
-    ZBNEG2(IW+1,:,:) = (PSRC(IW,  :,:) - PSRC(IW+1,:,:))**2
-!
-    ZOMP1(IW+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW+1,:,:))**2
-    ZOMP2(IW+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW+1,:,:))**2
-    ZOMN1(IW+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW+1,:,:))**2
-    ZOMN2(IW+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW+1,:,:))**2
-!
-    PR(IW+1,:,:) = (ZOMP2(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)) *         & 
-      ZFPOS2(IW+1,:,:)                                                          & 
-      + ZOMP1(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)) * ZFPOS1(IW+1,:,:)) * &
-      (0.5+SIGN(0.5,PRUCT(IW+1,:,:)))                                           &
-      + (ZOMN2(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)) * ZFNEG2(IW+1,:,:)   &
-      + ZOMN1(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)) * ZFNEG1(IW+1,:,:)) * &
-      (0.5-SIGN(0.5,PRUCT(IW+1,:,:)))
-!
-! PROC. BORDER (WEST) 
-!
-  ELSEIF (NHALO == 1) THEN
-!
-!   THIRD ORDER UPSTREAM WENO SCHEME
-!
-    ZFPOS1(IW,:,:) = 0.5 * (3.0*PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))
-    ZFPOS2(IW,:,:) = 0.5 * (PSRC(IW-1,    :,:)    + PSRC(IW,:,:))
-    ZBPOS1(IW,:,:) = (PSRC(IW-1,:,:) - TPHALO2%WEST(:,:))**2
-    ZBPOS2(IW,:,:) = (PSRC(IW,  :,:) - PSRC(IW-1,:,:))**2
-!
-    ZFNEG1(IW,:,:) = 0.5 * (3.0*PSRC(IW,:,:) - PSRC(IW+1,:,:))
-    ZFNEG2(IW,:,:) = 0.5 * (PSRC(IW,    :,:) + PSRC(IW-1,:,:))
-    ZBNEG1(IW,:,:) = (PSRC(IW,  :,:) - PSRC(IW+1,:,:))**2
-    ZBNEG2(IW,:,:) = (PSRC(IW-1,:,:) - PSRC(IW,  :,:))**2
-!
-    ZOMP1(IW,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IW,:,:))**2
-    ZOMP2(IW,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IW,:,:))**2
-    ZOMN1(IW,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IW,:,:))**2
-    ZOMN2(IW,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IW,:,:))**2
-!
-    PR(IW,:,:) = (ZOMP2(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS2(IW,:,:) &
-                + ZOMP1(IW,:,:)/(ZOMP1(IW,:,:)+ZOMP2(IW,:,:)) * ZFPOS1(IW,:,:))&
-                                               * (0.5+SIGN(0.5,PRUCT(IW,:,:))) &
-               + (ZOMN2(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG2(IW,:,:) &
-                + ZOMN1(IW,:,:)/(ZOMN1(IW,:,:)+ZOMN2(IW,:,:)) * ZFNEG1(IW,:,:))&
-                                               * (0.5-SIGN(0.5,PRUCT(IW,:,:)))
-!
-!   FIFTH ORDER UPSTREAM WENO SCHEME
-!
-    ZFPOS1(IW+1,:,:) = 1./6. *(2.0*TPHALO2%WEST(:,:)-7.0*PSRC(IW-1,:,:)+ &
-                       11.0*PSRC(IW, :,:))
-    ZFPOS2(IW+1,:,:) = 1./6. *(-PSRC(IW-1,  :,:)+ 5.0*PSRC(IW,  :,:)+    &
-                       2.0*PSRC(IW+1,:,:))
-    ZFPOS3(IW+1,:,:) = 1./6. *(2.0*PSRC(IW,  :,:)+5.0*PSRC(IW+1,:,:)-    &
-                       PSRC(IW+2,    :,:))
-!
-    ZBPOS1(IW+1,:,:) = 13./12. *(TPHALO2%WEST(:,:)-2.0*PSRC(IW-1,:,:)+   &
-                       PSRC(IW,:,:))**2 &
-                       + 1./4. *(TPHALO2%WEST(:,:)-4.0*PSRC(IW-1,:,:)+   &
-                       3.0*PSRC(IW,:,:))**2    
-    ZBPOS2(IW+1,:,:) = 13./12. *(PSRC(IW-1,:,:)   -2.0*PSRC(IW,:,:)+     &
-                       PSRC(IW+1,:,:))**2 &
-                       + 1./4. *(PSRC(IW-1,:,:) - PSRC(IW+1,:,:))**2
-    ZBPOS3(IW+1,:,:) = 13./12. *(PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) +     &
-                       PSRC(IW+2,:,:))**2 &
-                       + 1./4. *(3.0*PSRC(IW,:,:) - 4.0*PSRC(IW+1,:,:) + &
-                       PSRC(IW+2,:,:))**2
-!
-    ZFNEG1(IW+1,:,:) = 1./6 * (11.0*PSRC(IW+1,:,:) - 7.0*PSRC(IW+2,:,:) + &
-                       2.0*PSRC(IW+3,:,:))
-    ZFNEG2(IW+1,:,:) = 1./6 * (2.0*PSRC(IW, :,:) + 5.0*PSRC(IW+1,:,:) -   &
-                       PSRC(IW+2,    :,:))
-    ZFNEG3(IW+1,:,:) = 1./6 * (-PSRC(IW-1  ,:,:) + 5.0*PSRC(IW,  :,:) +   &
-                       2.0*PSRC(IW+1,:,:))
-!
-    ZBNEG1(IW+1,:,:) = 13./12 * (PSRC(IW+1,:,:) - 2.0*PSRC(IW+2,:,:) +    &
-                       PSRC(IW+3,:,:))**2 &
-                       + 1./4 * (3.0*PSRC(IW+1,:,:) - 4.0*PSRC(IW+2,:,:) +&
-                       PSRC(IW+3,:,:))**2
-    ZBNEG2(IW+1,:,:) = 13./12 * (PSRC(IW,:,:) - 2.0*PSRC(IW+1,:,:) +      &
-                       PSRC(IW+2,:,:))**2 &
-                       + 1./4 * (PSRC(IW,:,:) - PSRC(IW+2,:,:))**2
-    ZBNEG3(IW+1,:,:) = 13./12 * (PSRC(IW-1,:,:) - 2.0*PSRC(IW,:,:) +      &
-                       PSRC(IW+1,:,:))**2 &
-                       + 1./4 * (PSRC(IW-1,:,:) - 4.0*PSRC(IW,:,:) +      &
-                       3.0*PSRC(IW+1,:,:))**2
-!
-    ZOMP1(IW+1,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW+1,:,:))**2
-    ZOMP2(IW+1,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW+1,:,:))**2
-    ZOMP3(IW+1,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW+1,:,:))**2
-    ZOMN1(IW+1,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW+1,:,:))**2
-    ZOMN2(IW+1,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW+1,:,:))**2
-    ZOMN3(IW+1,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW+1,:,:))**2
-!
-      PR(IW+1,:,:) = (ZOMP2(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)+ &
-                     ZOMP3(IW+1,:,:)) * ZFPOS2(IW+1,:,:)   &
-                   + ZOMP1(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)+ &
-                     ZOMP3(IW+1,:,:)) * ZFPOS1(IW+1,:,:)    &
-                   + ZOMP3(IW+1,:,:)/(ZOMP1(IW+1,:,:)+ZOMP2(IW+1,:,:)+ &
-                     ZOMP3(IW+1,:,:)) * ZFPOS3(IW+1,:,:)) * &
-                   (0.5+SIGN(0.5,PRUCT(IW+1,:,:)))                     &
-                  + (ZOMN2(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)+ &
-                     ZOMN3(IW+1,:,:)) * ZFNEG2(IW+1,:,:)    &
-                   + ZOMN1(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)+ &
-                     ZOMN3(IW+1,:,:)) * ZFNEG1(IW+1,:,:)    &
-                   + ZOMN3(IW+1,:,:)/(ZOMN1(IW+1,:,:)+ZOMN2(IW+1,:,:)+ &
-                     ZOMN3(IW+1,:,:)) * ZFNEG3(IW+1,:,:)) * &
-                   (0.5-SIGN(0.5,PRUCT(IW+1,:,:)))
-!
-  ENDIF
-!
-! PHYSICAL BORDER (EAST)
-!
-  IF(LEAST_ll()) THEN
-    PR(IE+1,:,:) = PSRC(IE,:,:) * (0.5+SIGN(0.5,PRUCT(IE+1,:,:))) + &
+ IF(LWEST_ll()  .AND. .FALSE. ) THEN  ! West border is physical 
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE
+ ZFPOS3(IE+1,:,:) = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IW,:,:)) ! Flux IE+1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBPOS3(IE+1,:,:) = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2  ! Smoothness indicator IE+1
+ ZOMP3(IE:IE+1,:,:) = 3./10. / (ZEPS + ZBPOS3(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IW,:,:)) ! Flux IE
+ ZFNEG1(IE+1,:,:) = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IW,:,:)   + 2.0*PSRC(IW+1,:,:)) ! Flux IE+1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2  ! Smoothness indicator IE
+ ZBNEG1(IE+1,:,:) = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IW,:,:) + PSRC(IW+1,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN1(IE:IE+1,:,:) = 1./10. / (ZEPS + ZBNEG1(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZFNEG2(IE+1,:,:) = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IW,:,:)) ! Flux IE+1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBNEG2(IE+1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IW,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IW,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN2(IE:IE+1,:,:) = 3./5. / (ZEPS + ZBNEG2(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ELSEIF(IE<=SIZE(PSRC,1)-3) THEN ! West boundary is proc border, with minimum 3 HALO points on east side
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE
+ ZFPOS3(IE+1,:,:) = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IE+2,:,:)) ! Flux IE+1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBPOS3(IE+1,:,:) = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE+1
+ ZOMP3(IE:IE+1,:,:) = 3./10. / (ZEPS + ZBPOS3(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IE+2,:,:)) ! Flux IE
+ ZFNEG1(IE+1,:,:) = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IE+2,:,:)   + 2.0*PSRC(IE+3,:,:)) ! Flux IE+1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE
+ ZBNEG1(IE+1,:,:) = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN1(IE:IE+1,:,:) = 1./10. / (ZEPS + ZBNEG1(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZFNEG2(IE+1,:,:) = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IE+2,:,:)) ! Flux IE+1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBNEG2(IE+1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IE+2,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN2(IE:IE+1,:,:) = 3./5. / (ZEPS + ZBNEG2(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ELSE ! West boundary is proc border, with NHALO < 3 on east side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on east side'
+  CALL ABORT
+ ENDIF
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(IE,:,:)   = 1./6. * (2.0*PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + 11.0*PSRC(IE-1,:,:)) ! Flux IE
+ ZFPOS1(IE+1,:,:) = 1./6. * (2.0*PSRC(IE-2,:,:) - 7.0*PSRC(IE-1,:,:) + 11.0*PSRC(IE,:,:)) ! Flux IE+1
+ ZBPOS1(IE,:,:)   = 13./12. * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) +     PSRC(IE-1,:,:))**2 & 
+        + 1./4    * (PSRC(IE-3,:,:) - 4.0*PSRC(IE-2,:,:) + 3.0*PSRC(IE-1,:,:))**2  ! Smoothness indicator IE
+ ZBPOS1(IE+1,:,:) = 13./12. * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 & 
+        + 1./4    * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2  ! Smoothness indicator IE+1
+ ZOMP1(IE:IE+1,:,:) = 1./10. / (ZEPS + ZBPOS1(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(IE,:,:)   = 1./6. * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE
+ ZFPOS2(IE+1,:,:) = 1./6. * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE+1
+ ZBPOS2(IE,:,:)   = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + PSRC(IE,:,:))**2 &
+      + 1./4   * (PSRC(IE-2,:,:) -                      PSRC(IE,:,:))**2 ! Smoothness indicator IE
+ ZBPOS2(IE+1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                   PSRC(IE+1,:,:))**2 ! Smoothness indicator IE+1
+ ZOMP2(IE:IE+1,:,:)  = 3./5. / (ZEPS + ZBPOS2(IE:IE+1,:,:))**2  ! Non-normalized weight IE,IE+1
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(IE,:,:)   = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE
+ ZFNEG3(IE+1,:,:) = 1./6 * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE+1
+ ZBNEG3(IE,:,:)   = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 &
+        + 1./4   * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2 ! Smoothness indicator IE
+ ZBNEG3(IE+1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IE+1,:,:))**2 &
+        + 1./4   * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IE+1,:,:))**2 ! Smoothness indicator IE+1
+ ZOMN3(IE:IE+1,:,:) = 3./10. / (ZEPS + ZBNEG3(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! ----- Total flux -----
+! 
+ PR(IE:IE+1,:,:) = ( ZOMP1(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS1(IE:IE+1,:,:) &
+                       + ZOMP2(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS2(IE:IE+1,:,:) & 
+                       + ZOMP3(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS3(IE:IE+1,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IE:IE+1,:,:))) &
+                    + ( ZOMN1(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG1(IE:IE+1,:,:) &
+                       + ZOMN2(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG2(IE:IE+1,:,:) &
+                       + ZOMN3(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG3(IE:IE+1,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IE:IE+1,:,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IE+1
+    PR(IE+1,:,:) = PSRC(IE,:,:)  * (0.5+SIGN(0.5,PRUCT(IE+1,:,:))) + &
                    PSRC(IE+1,:,:) * (0.5-SIGN(0.5,PRUCT(IE+1,:,:)))
 !
-    ZFPOS1(IE,:,:) = 0.5 * (3.0*PSRC(IE-1,:,:) - PSRC(IE-2,:,:))
-    ZFPOS2(IE,:,:) = 0.5 * (PSRC(IE,      :,:) + PSRC(IE-1,:,:))
-    ZBPOS1(IE,:,:) = (PSRC(IE-1,:,:) - PSRC(IE-2,:,:))**2
-    ZBPOS2(IE,:,:) = (PSRC(IE,  :,:) - PSRC(IE-1,:,:))**2
-!
-    ZFNEG1(IE,:,:) = 0.5 * (3.0*PSRC(IE,:,:) - PSRC(IE+1,:,:))
-    ZFNEG2(IE,:,:) = 0.5 * (PSRC(IE,    :,:) + PSRC(IE-1,:,:))
-    ZBNEG1(IE,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,:,:))**2
-    ZBNEG2(IE,:,:) = (PSRC(IE-1,:,:) - PSRC(IE,  :,:))**2
-!
-    ZOMP1(IE,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE,:,:))**2
-    ZOMP2(IE,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE,:,:))**2
-    ZOMN1(IE,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE,:,:))**2
-    ZOMN2(IE,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE,:,:))**2
-!
-    PR(IE,:,:) = (ZOMP2(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)) * ZFPOS2(IE,:,:) + &
-                  ZOMP1(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)) * ZFPOS1(IE,:,:)) *&
-                  (0.5+SIGN(0.5,PRUCT(IE,:,:))) &
-               + (ZOMN2(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)) * ZFNEG2(IE,:,:) + &
-                  ZOMN1(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)) * ZFNEG1(IE,:,:)) *&
-                  (0.5-SIGN(0.5,PRUCT(IE,:,:)))
-!
-! PROC. BORDER (EAST) 
-!
-  ELSEIF(NHALO == 1) THEN
-    ZFPOS1(IE+1,:,:) = 0.5 * (3.0*PSRC(IE,:,:) - PSRC(IE-1,:,:))
-    ZFPOS2(IE+1,:,:) = 0.5 * (PSRC(IE+1,  :,:) + PSRC(IE,  :,:))
-    ZBPOS1(IE+1,:,:) = (PSRC(IE,  :,:) - PSRC(IE-1,:,:))**2
-    ZBPOS2(IE+1,:,:) = (PSRC(IE+1,:,:) - PSRC(IE,  :,:))**2
-!
-    ZFNEG1(IE+1,:,:) = 0.5 * (3.0*PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))
-    ZFNEG2(IE+1,:,:) = 0.5 * (PSRC(IE+1,    :,:) + PSRC(IE,     :,:))
-    ZBNEG1(IE+1,:,:) = (PSRC(IE+1,:,:) - TPHALO2%EAST(:,:))**2
-    ZBNEG2(IE+1,:,:) = (PSRC(IE,  :,:) - PSRC(IE+1,   :,:))**2
-!
-    ZOMP1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(IE+1,:,:))**2
-    ZOMP2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(IE+1,:,:))**2
-    ZOMN1(IE+1,:,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(IE+1,:,:))**2
-    ZOMN2(IE+1,:,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(IE+1,:,:))**2
-!
-    PR(IE+1,:,:) = (ZOMP2(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) * &
-                    ZFPOS2(IE+1,:,:) +                                  &
-                  ZOMP1(IE+1,:,:)/(ZOMP1(IE+1,:,:)+ZOMP2(IE+1,:,:)) *   &
-                  ZFPOS1(IE+1,:,:)) * (0.5+SIGN(0.5,PRUCT(IE+1,:,:)))   &
-               + (ZOMN2(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) *   &
-                ZFNEG2(IE+1,:,:) +                                      &
-                  ZOMN1(IE+1,:,:)/(ZOMN1(IE+1,:,:)+ZOMN2(IE+1,:,:)) *   &
-                  ZFNEG1(IE+1,:,:)) * (0.5-SIGN(0.5,PRUCT(IE+1,:,:)))
-!
-     ZFPOS1(IE,:,:) = 1./6 * (2.0*PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + &
-                      11.0*PSRC(IE-1,:,:))
-     ZFPOS2(IE,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + &
-                      2.0*PSRC(IE,:,:))
-     ZFPOS3(IE,:,:) = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) -    &
-                      PSRC(IE+1,:,:))
-!
-     ZBPOS1(IE,:,:) = 13./12 * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) + &
-                      PSRC(IE-1,:,:))**2 + 1./4 * (PSRC(IE-3,:,:) &
-                      - 4.0*PSRC(IE-2,:,:) + 3.0*PSRC(IE-1,:,:))**2
-     ZBPOS2(IE,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + &
-                      PSRC(IE,:,:))**2 + 1./4 * &
-                     (PSRC(IE-2,:,:) - PSRC(IE,:,:))**2
-     ZBPOS3(IE,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + &
-                      PSRC(IE+1,:,:))**2 + 1./4 * &
-                     ( 3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2
-!
-     ZFNEG1(IE,:,:) = 1./6 * (11.0*PSRC(IE,  :,:) - 7.0*PSRC(IE+1,:,:) + &
-                      2.0*TPHALO2%EAST(:,:))
-     ZFNEG2(IE,:,:) = 1./6 * (2.0*PSRC(IE-1, :,:) + 5.0*PSRC(IE,  :,:) - &
-                      PSRC(IE+1,:,:))
-     ZFNEG3(IE,:,:) = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + &
-                      2.0*PSRC(IE,:,:))
-!
-     ZBNEG1(IE,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) +      &
-       TPHALO2%EAST(:,:))**2 + 1./4 * &
-       ( 3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + TPHALO2%EAST(:,:))**2
-     ZBNEG2(IE,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +      &
-        PSRC(IE+1,:,:))**2 + 1./4 * &
-        (PSRC(IE-1,:,:) - PSRC(IE+1,:,:))**2
-     ZBNEG3(IE,:,:) = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +    &
-        PSRC(IE,:,:))**2 + 1./4 * &
-                      ( PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) +            &
-                      3.0*PSRC(IE,:,:))**2
-!
-     ZOMP1(IE,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IE,:,:))**2
-     ZOMP2(IE,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IE,:,:))**2
-     ZOMP3(IE,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IE,:,:))**2
-     ZOMN1(IE,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IE,:,:))**2
-     ZOMN2(IE,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IE,:,:))**2
-     ZOMN3(IE,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IE,:,:))**2
-!
-       PR(IE,:,:) = (ZOMP2(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)+ &
-                   ZOMP3(IE,:,:)) * ZFPOS2(IE,:,:)    &
-                   + ZOMP1(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)+ &
-                   ZOMP3(IE,:,:)) * ZFPOS1(IE,:,:)    &
-                   + ZOMP3(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:)+ &
-                   ZOMP3(IE,:,:)) * ZFPOS3(IE,:,:)) * &
-                   (0.5+SIGN(0.5,PRUCT(IE,:,:)))                 &
-                  + (ZOMN2(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)+ &
-                   ZOMN3(IE,:,:)) * ZFNEG2(IE,:,:)    &
-                   + ZOMN1(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)+ &
-                   ZOMN3(IE,:,:)) * ZFNEG1(IE,:,:)    &
-                   + ZOMN3(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:)+ &
-                   ZOMN3(IE,:,:)) * ZFNEG3(IE,:,:)) * &
-                   (0.5-SIGN(0.5,PRUCT(IE,:,:)))
-!
-  ENDIF
-!
-!        USE A FIFTH ORDER UPSTREAM WENO SCHEME ELSEWHERE (IW+2 --> IE-1)
-!
-  ZFPOS1(IW+2:IE-1,:,:) = 1./6 * (2.0*PSRC(IW-1:IE-4,:,:) - &
-          7.0*PSRC(IW:IE-3,  :,:) + 11.0*PSRC(IW+1:IE-2,:,:))
-  ZFPOS2(IW+2:IE-1,:,:) = 1./6 * (-1.0*PSRC(IW:IE-3, :,:) + &
-          5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1, :,:))
-  ZFPOS3(IW+2:IE-1,:,:) = 1./6 * (2.0*PSRC(IW+1:IE-2,:,:) + &
-          5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,       :,:))
-!
-  ZBPOS1(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW-1:IE-4,:,:) -   &
-          2.0*PSRC(IW:IE-3,:,:) + PSRC(IW+1:IE-2,:,:))**2 + &
-          1./4 * (PSRC(IW-1:IE-4,:,:) - 4.0*PSRC(IW:IE-3,:,:) + &
-          3.0*PSRC(IW+1:IE-2,:,:))**2
-  ZBPOS2(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW:IE-3,:,:) -     &
-          2.0*PSRC(IW+1:IE-2,:,:) + PSRC(IW+2:IE-1,:,:))**2 + &
-          1./4 * (PSRC(IW:IE-3,:,:) - PSRC(IW+2:IE-1,:,:))**2
-  ZBPOS3(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW+1:IE-2,:,:) -   &
-          2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 + &
-          1./4 * (3.0*PSRC(IW+1:IE-2,:,:) - 4.0*PSRC(IW+2:IE-1,:,:) + &
-          PSRC(IW+3:IE,:,:))**2
-!
-  ZFNEG1(IW+2:IE-1,:,:) = 1./6 * (11.0*PSRC(IW+2:IE-1,:,:) - &
-          7.0*PSRC(IW+3:IE,:,:) + 2.0*PSRC(IW+4:IE+1,:,:))
-  ZFNEG2(IW+2:IE-1,:,:) = 1./6 * (2.0*PSRC(IW+1:IE-2,:,:) +  &
-          5.0*PSRC(IW+2:IE-1,:,:) - PSRC(IW+3:IE,:,:))
-  ZFNEG3(IW+2:IE-1,:,:) = 1./6 * (-1.0*PSRC(IW:IE-3,:,:) +   &
-          5.0*PSRC(IW+1:IE-2,:,:) + 2.0*PSRC(IW+2:IE-1,:,:))
-!
-  ZBNEG1(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW+2:IE-1,:,:) -    &
-          2.0*PSRC(IW+3:IE,:,:) + PSRC(IW+4:IE+1,:,:))**2 + &
-          1./4 * ( 3.0*PSRC(IW+2:IE-1,:,:) - 4.0*PSRC(IW+3:IE,:,:) + &
-          PSRC(IW+4:IE+1,:,:))**2
-  ZBNEG2(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW+1:IE-2,:,:) - &
-          2.0*PSRC(IW+2:IE-1,:,:) + PSRC(IW+3:IE,:,:))**2 + &
-          1./4 * (PSRC(IW+1:IE-2,:,:) - PSRC(IW+3:IE,:,:))**2
-  ZBNEG3(IW+2:IE-1,:,:) = 13./12 * (PSRC(IW:IE-3,:,:) - &
-          2.0*PSRC(IW+1:IE-2,:,:) + PSRC(IW+2:IE-1,:,:))**2 + &
-          1./4 * ( PSRC(IW:IE-3,:,:) - 4.0*PSRC(IW+1:IE-2,:,:) + &
-          3.0*PSRC(IW+2:IE-1,:,:))**2
-!
-  ZOMP1(IW+2:IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBPOS1(IW+2:IE-1,:,:))**2
-  ZOMP2(IW+2:IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBPOS2(IW+2:IE-1,:,:))**2
-  ZOMP3(IW+2:IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBPOS3(IW+2:IE-1,:,:))**2
-  ZOMN1(IW+2:IE-1,:,:) = ZGAMMA1 / (ZEPS + ZBNEG1(IW+2:IE-1,:,:))**2
-  ZOMN2(IW+2:IE-1,:,:) = ZGAMMA2 / (ZEPS + ZBNEG2(IW+2:IE-1,:,:))**2
-  ZOMN3(IW+2:IE-1,:,:) = ZGAMMA3 / (ZEPS + ZBNEG3(IW+2:IE-1,:,:))**2
-!
-    PR(IW+2:IE-1,:,:) = (ZOMP2(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+   &
-      ZOMP2(IW+2:IE-1,:,:)+                                            &
-      ZOMP3(IW+2:IE-1,:,:)) * ZFPOS2(IW+2:IE-1,:,:) +                  &
-      ZOMP1(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+ZOMP2(IW+2:IE-1,:,:)+ &
-      ZOMP3(IW+2:IE-1,:,:)) * ZFPOS1(IW+2:IE-1,:,:)  +                 &
-      ZOMP3(IW+2:IE-1,:,:)/(ZOMP1(IW+2:IE-1,:,:)+ZOMP2(IW+2:IE-1,:,:)+ &
-      ZOMP3(IW+2:IE-1,:,:)) * ZFPOS3(IW+2:IE-1,:,:)) *                 &
-      (0.5+SIGN(0.5,PRUCT(IW+2:IE-1,:,:))) +                           &
-      (ZOMN2(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+&
-      ZOMN3(IW+2:IE-1,:,:)) * ZFNEG2(IW+2:IE-1,:,:)  +                 &
-      ZOMN1(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+ &
-      ZOMN3(IW+2:IE-1,:,:)) * ZFNEG1(IW+2:IE-1,:,:) +                  &
-      ZOMN3(IW+2:IE-1,:,:)/(ZOMN1(IW+2:IE-1,:,:)+ZOMN2(IW+2:IE-1,:,:)+ &
-      ZOMN3(IW+2:IE-1,:,:)) * ZFNEG3(IW+2:IE-1,:,:)) *                 &
-      (0.5-SIGN(0.5,PRUCT(IW+2:IE-1,:,:)))
-!
-END SELECT
-!
-PR = PR * PRUCT
+!   ! WENO scheme order 3, IE
+    ZFPOS1(IE,:,:) = 0.5 * (3.0*PSRC(IE-1,:,:) - PSRC(IE-2,:,:)) ! First positive flux
+    ZFPOS2(IE,:,:) = 0.5 * ( PSRC(IE-1,:,:) + PSRC(IE,:,:)) ! Second positive flux
+    ZBPOS1(IE,:,:) = (PSRC(IE-1,:,:) - PSRC(IE-2,:,:))**2 ! First positive smoothness indicator
+    ZBPOS2(IE,:,:) = (PSRC(IE,:,:)   - PSRC(IE-1,:,:))**2 ! Second positive smoothness indicator
+!
+    ZFNEG1(IE,:,:) = 0.5 * (3.0*PSRC(IE,:,:)   - PSRC(IE+1,:,:)) ! First negative flux
+    ZFNEG2(IE,:,:) = 0.5 * ( PSRC(IE-1,:,:) + PSRC(IE,:,:)) ! Second negative flux
+    ZBNEG1(IE,:,:) = (PSRC(IE,:,:)   - PSRC(IE+1,:,:))**2 ! First negative smoothness indicator
+    ZBNEG2(IE,:,:) = (PSRC(IE-1,:,:) - PSRC(IE,:,:))**2  ! Second negative smoothness indicator
+!
+    ZOMP1(IE,:,:) = 1./3. / (ZEPS + ZBPOS1(IE,:,:))**2 ! First positive non-normalized weight
+    ZOMP2(IE,:,:) = 2./3. / (ZEPS + ZBPOS2(IE,:,:))**2 ! Second positive non-normalized weight
+    ZOMN1(IE,:,:) = 1./3. / (ZEPS + ZBNEG1(IE,:,:))**2 ! First negative non-normalized weight
+    ZOMN2(IE,:,:) = 2./3. / (ZEPS + ZBNEG2(IE,:,:))**2 ! Second negative non-normalized weight
+! 
+    PR(IE,:,:) = (ZOMN2(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:))*ZFNEG2(IE,:,:) + &
+     (ZOMN1(IE,:,:)/(ZOMN1(IE,:,:)+ZOMN2(IE,:,:))*ZFNEG1(IE,:,:))) &
+     *(0.5-SIGN(0.5,PRUCT(IE,:,:))) + &
+                 (ZOMP2(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:))*ZFPOS2(IE,:,:) + &
+                 (ZOMP1(IE,:,:)/(ZOMP1(IE,:,:)+ZOMP2(IE,:,:))*ZFPOS1(IE,:,:))) &
+     *(0.5+SIGN(0.5,PRUCT(IE,:,:)))  ! Total flux
+! 
+ END SELECT ! SELECT CASE (HLBCX(2)) ! X direction LBC type on right side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! East border is proc border -- IE,IE+1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >= 3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+! 
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(IE,:,:)   = 1./6. * (2.0*PSRC(IE-3,:,:) - 7.0*PSRC(IE-2,:,:) + 11.0*PSRC(IE-1,:,:)) ! Flux IE
+ ZFPOS1(IE+1,:,:) = 1./6. * (2.0*PSRC(IE-2,:,:) - 7.0*PSRC(IE-1,:,:) + 11.0*PSRC(IE,:,:)) ! Flux IE+1
+ ZBPOS1(IE,:,:)   = 13./12. * (PSRC(IE-3,:,:) - 2.0*PSRC(IE-2,:,:) +     PSRC(IE-1,:,:))**2 & 
+        + 1./4    * (PSRC(IE-3,:,:) - 4.0*PSRC(IE-2,:,:) + 3.0*PSRC(IE-1,:,:))**2  ! Smoothness indicator IE
+ ZBPOS1(IE+1,:,:) = 13./12. * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 & 
+        + 1./4    * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2  ! Smoothness indicator IE+1
+ ZOMP1(IE:IE+1,:,:) = 1./10. / (ZEPS + ZBPOS1(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(IE,:,:)   = 1./6. * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE
+ ZFPOS2(IE+1,:,:) = 1./6. * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE+1
+ ZBPOS2(IE,:,:)   = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) + PSRC(IE,:,:))**2 &
+      + 1./4   * (PSRC(IE-2,:,:) -                      PSRC(IE,:,:))**2 ! Smoothness indicator IE
+ ZBPOS2(IE+1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                   PSRC(IE+1,:,:))**2 ! Smoothness indicator IE+1
+ ZOMP2(IE:IE+1,:,:)  = 3./5. / (ZEPS + ZBPOS2(IE:IE+1,:,:))**2  ! Non-normalized weight IE,IE+1
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(IE,:,:)   = 1./6 * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:) - PSRC(IE+1,:,:)) ! Flux IE
+ ZFPOS3(IE+1,:,:) = 1./6 * (2.0*PSRC(IE,:,:) + 5.0*PSRC(IE+1,:,:) - PSRC(IE+2,:,:)) ! Flux IE+1
+ ZBPOS3(IE,:,:)   = 13./12 * (    PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBPOS3(IE+1,:,:) = 13./12 * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE+1
+ ZOMP3(IE:IE+1,:,:) = 3./10. / (ZEPS + ZBPOS3(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(IE,:,:)   = 1./6. * (11.0*PSRC(IE,:,:)   - 7.0*PSRC(IE+1,:,:) + 2.0*PSRC(IE+2,:,:)) ! Flux IE
+ ZFNEG1(IE+1,:,:) = 1./6. * (11.0*PSRC(IE+1,:,:) - 7.0*PSRC(IE+2,:,:)   + 2.0*PSRC(IE+3,:,:)) ! Flux IE+1
+ ZBNEG1(IE,:,:)   = 13./12. * (    PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE,:,:) - 4.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2  ! Smoothness indicator IE
+ ZBNEG1(IE+1,:,:) = 13./12. * (    PSRC(IE+1,:,:) - 2.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2 & 
+      + 1./4    * (3.0*PSRC(IE+1,:,:) - 4.0*PSRC(IE+2,:,:) + PSRC(IE+3,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN1(IE:IE+1,:,:) = 1./10. / (ZEPS + ZBNEG1(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(IE,:,:)   = 1./6. * (2.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   - 1.0*PSRC(IE+1,:,:)) ! Flux IE
+ ZFNEG2(IE+1,:,:) = 1./6. * (2.0*PSRC(IE,:,:)   + 5.0*PSRC(IE+1,:,:) - 1.0*PSRC(IE+2,:,:)) ! Flux IE+1
+ ZBNEG2(IE,:,:)   = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) + PSRC(IE+1,:,:))**2 &
+      + 1./4   * (PSRC(IE-1,:,:) -                    PSRC(IE+1,:,:))**2 ! Smoothness indicator IE
+ ZBNEG2(IE+1,:,:) = 13./12 * (PSRC(IE,:,:) - 2.0*PSRC(IE+1,:,:) + PSRC(IE+2,:,:))**2 &
+      + 1./4   * (PSRC(IE,:,:) -                      PSRC(IE+2,:,:))**2  ! Smoothness indicator IE+1
+ ZOMN2(IE:IE+1,:,:) = 3./5. / (ZEPS + ZBNEG2(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(IE,:,:)   = 1./6 * (-1.0*PSRC(IE-2,:,:) + 5.0*PSRC(IE-1,:,:) + 2.0*PSRC(IE,:,:)) ! Flux IE
+ ZFNEG3(IE+1,:,:) = 1./6 * (-1.0*PSRC(IE-1,:,:) + 5.0*PSRC(IE,:,:)   + 2.0*PSRC(IE+1,:,:)) ! Flux IE+1
+ ZBNEG3(IE,:,:)   = 13./12 * (PSRC(IE-2,:,:) - 2.0*PSRC(IE-1,:,:) +     PSRC(IE,:,:))**2 &
+        + 1./4   * (PSRC(IE-2,:,:) - 4.0*PSRC(IE-1,:,:) + 3.0*PSRC(IE,:,:))**2 ! Smoothness indicator IE
+ ZBNEG3(IE+1,:,:) = 13./12 * (PSRC(IE-1,:,:) - 2.0*PSRC(IE,:,:) +     PSRC(IE+1,:,:))**2 &
+        + 1./4   * (PSRC(IE-1,:,:) - 4.0*PSRC(IE,:,:) + 3.0*PSRC(IE+1,:,:))**2 ! Smoothness indicator IE+1
+ ZOMN3(IE:IE+1,:,:) = 3./10. / (ZEPS + ZBNEG3(IE:IE+1,:,:))**2 ! Non-normalized weight IE,IE+1
+!
+ ! ----- Total flux -----
+! 
+ PR(IE:IE+1,:,:) = ( ZOMP1(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS1(IE:IE+1,:,:) &
+                       + ZOMP2(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS2(IE:IE+1,:,:) & 
+                       + ZOMP3(IE:IE+1,:,:)/(ZOMP1(IE:IE+1,:,:)+ZOMP2(IE:IE+1,:,:)+ZOMP3(IE:IE+1,:,:)) * ZFPOS3(IE:IE+1,:,:)) &
+                      * (0.5+SIGN(0.5,PRUCT(IE:IE+1,:,:))) &
+                    + ( ZOMN1(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG1(IE:IE+1,:,:) &
+                       + ZOMN2(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG2(IE:IE+1,:,:) &
+                       + ZOMN3(IE:IE+1,:,:)/(ZOMN1(IE:IE+1,:,:)+ZOMN2(IE:IE+1,:,:)+ZOMN3(IE:IE+1,:,:)) * ZFNEG3(IE:IE+1,:,:)) &
+                      * (0.5-SIGN(0.5,PRUCT(IE:IE+1,:,:)))
+!
+ END IF ! NHALO
+!
+END IF ! IF(LWEST_ll()) 
+!-------------------------------------------------------------------------------
+!
+PR = PR * PRUCT ! Add contravariant flux
 !
 END SUBROUTINE ADVEC_WENO_K_3_MX
 !
 !-------------------------------------------------------------------------------
 !
 !     ########################################################################
-      SUBROUTINE ADVEC_WENO_K_3_MY(HLBCY,PSRC, PRVCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_MY(HLBCY,PSRC, PRVCT, PR)
 !     ########################################################################
 !!
 !!****  Computes PRVCT * PUT (or PRVCT * PWT). Upstream fluxes of U (or W) 
@@ -1387,13 +1428,16 @@ END SUBROUTINE ADVEC_WENO_K_3_MX
 !!
 !!    MODIFICATIONS
 !!    -------------
+!! T. Lunet 02/10/2014:  Correction of periodic boudary conditions
+!!       Change of structure in order to adapt WENO to NHALOK
+!!       Suppression of second layer HALO pointers
+!!       Complete code documentation
 !!
 !-------------------------------------------------------------------------------
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 IMPLICIT NONE
 !
@@ -1407,7 +1451,6 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRVCT ! contrav. comp. on MASS GRID
 ! output source term
 !
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 !*       0.2   Declarations of local variables :
 !
@@ -1423,7 +1466,6 @@ INTEGER:: ILUOUT,IRESP   ! for prints
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -1436,15 +1478,11 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMN1, ZOMN2, ZOMN3
+
+REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZWORK
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
+! EPSILON for weno weights calculation
+! 
 REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !-----------------------------------------------------------------------------
@@ -1479,478 +1517,563 @@ ZOMP3  = 0.0
 ZOMN1  = 0.0
 ZOMN2  = 0.0
 ZOMN3  = 0.0 
+
+ZWORK = 0.0
 !
 !-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
+IS=IJB
+IN=IJE
 !
-SELECT CASE ( HLBCY(1) ) ! 
-!
-!*       1.1    CYCLIC CASE IN THE Y DIRECTION:
-!
-CASE ('CYCL')          ! In that case one must have HLBCY(1) == HLBCY(2)
-!
-  IF(NHALO == 1) THEN
-    IS=IJB
-    IN=IJE
-  ELSE
-      CALL FMLOOK_ll(CLUOUT0,CLUOUT0,ILUOUT,IRESP)
-      WRITE(ILUOUT,*) 'ERROR : 4th order advection in CYCLic case '
-      WRITE(ILUOUT,*) 'cannot be used with NHALO=2'
-      CALL ABORT
-      STOP
-  END IF
-!
-! Same explanation than for the subroutine ADVEC_WENO_K_3_MX
-!
-! intermediate fluxes for positive wind case
-!
-  ZFPOS1(:,IS+2:IN,:) = 1./6 * (2.0*PSRC(:,IS-1:IN-3,:) - &
-   7.0*PSRC(:,IS:IN-2,:) + 11.0*PSRC(:,IS+1:IN-1,:))
-  ZFPOS1(:,IS+1,   :) = 1./6 * (2.0*TPHALO2%SOUTH(:,:)  - &
-   7.0*PSRC(:,IS-1,   :) + 11.0*PSRC(:,IS,       :))
-  ZFPOS1(:,IN+1,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN-1,:))
-  ZFPOS1(:,IS,       :) = 0.5 * (3.0*PSRC(:,IS-1, :) - TPHALO2%SOUTH(:,:))
-  ZFPOS1(:,IS-1,     :) = - 999.
-!
-!
-  ZFPOS2(:,IS+1:IN,:) = 1./6 * (-1.0*PSRC(:,IS-1:IN-2,:) + &
-   5.0*PSRC(:,IS:IN-1,:) + 2.0*PSRC(:,IS+1:IN,:))
-  ZFPOS2(:,IN+1,:) = 0.5 * (PSRC(:,IN,  :) + PSRC(:,IN+1,:))
-  ZFPOS2(:,IS,  :) = 0.5 * (PSRC(:,IS-1,:) + PSRC(:,IS,  :))
-  ZFPOS2(:,IS-1,:) = 0.5 * (TPHALO2%SOUTH(:,:) + PSRC(:,IS-1,:))
-!
-!
-  ZFPOS3(:,IS+1:IN,:) = 1./6 * (2.0*PSRC(:,IS:IN-1,:) + &
-   5.0*PSRC(:,IS+1:IN,:) - 1.0*PSRC(:,IS+2:IN+1,:))
-!
-! intermediate flux for negative wind case
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IS+2 -> IN-1
+! Computation at the mass point on Vgrid v(i-1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-  ZFNEG1(:,IS+1:IN-1,:) = 1./6 * (11.0*PSRC(:,IS+1:IN-1,:) - &
-   7.0*PSRC(:,IS+2:IN,:) + 2.0*PSRC(:,IS+3:IN+1,:)) 
-  ZFNEG1(:,IN,       :) = 1./6 * (11.0*PSRC(:,IN,       :) - &
-   7.0*PSRC(:,IN+1,   :) + 2.0*TPHALO2%NORTH(:,:))
-  ZFNEG1(:,IS,  :) = 0.5 * (3.0*PSRC(:,IS,  :) - PSRC(:,IS+1,:))
-  ZFNEG1(:,IS-1,:) = 0.5 * (3.0*PSRC(:,IS-1,:) - PSRC(:,IS,  :))
-  ZFNEG1(:,IN+1,:) = 0.5 * (3.0*PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-3, i-2, i-1
+ZFPOS1(:,IS+2:IN-1,:) = 1./6.   * (2.0*PSRC(:,IS-1:IN-4,:)- 7.0*PSRC(:,IS:IN-3,:)+ 11.0*PSRC(:,IS+1:IN-2,:))   ! Flux
+ZBPOS1(:,IS+2:IN-1,:) = 13./12. * (    PSRC(:,IS-1:IN-4,:)- 2.0*PSRC(:,IS:IN-3,:)+      PSRC(:,IS+1:IN-2,:))**2 &
+      + 1./4    * (    PSRC(:,IS-1:IN-4,:)- 4.0*PSRC(:,IS:IN-3,:)+ 3.0* PSRC(:,IS+1:IN-2,:))**2  ! Smoothness indicator
+ZOMP1(:,IS+2:IN-1,:)  = 1./10. /  (ZEPS + ZBPOS1(:,IS+2:IN-1,:))**2             ! Non-normalized weight
+!
+! Second positive stencil, needs indices i-2, i-1, i
+ZFPOS2(:,IS+2:IN-1,:) = 1./6.  * (-1.0*PSRC(:,IS:IN-3,:) + 5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))  ! Flux
+ZBPOS2(:,IS+2:IN-1,:) = 13./12 * (     PSRC(:,IS:IN-3,:) - 2.0*PSRC(:,IS+1:IN-2,:) +     PSRC(:,IS+2:IN-1,:))**2 &
+      + 1./4   * (     PSRC(:,IS:IN-3,:) -                               PSRC(:,IS+2:IN-1,:))**2 ! Smoothness indicator
+ZOMP2(:,IS+2:IN-1,:)  = 3./5. /  (ZEPS + ZBPOS2(:,IS+2:IN-1,:))**2             ! Non-normalized weight
+!
+! Third positive stencil, needs indices i-1, i, i+1
+ZFPOS3(:,IS+2:IN-1,:) = 1./6   * (2.0*PSRC(:,IS+1:IN-2,:) + 5.0*PSRC(:,IS+2:IN-1,:) - PSRC(:,IS+3:IN,:))  ! Flux
+ZBPOS3(:,IS+2:IN-1,:) = 13./12 * ( PSRC(:,IS+1:IN-2,:) - 2.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS+1:IN-2,:) - 4.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 ! Smoothness indicator
+ZOMP3(:,IS+2:IN-1,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS+2:IN-1,:))**2           ! Non-normalized weight
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i, i+1, i+2
+ZFNEG1(:,IS+2:IN-1,:) = 1./6.   * (11.0*PSRC(:,IS+2:IN-1,:) - 7.0*PSRC(:,IS+3:IN,:) + 2.0*PSRC(:,IS+4:IN+1,:))   ! Flux
+ZBNEG1(:,IS+2:IN-1,:) = 13./12. * (     PSRC(:,IS+2:IN-1,:) - 2.0*PSRC(:,IS+3:IN,:) +     PSRC(:,IS+4:IN+1,:))**2 &
+      + 1./4    * (3.0* PSRC(:,IS+2:IN-1,:) - 4.0*PSRC(:,IS+3:IN,:) +     PSRC(:,IS+4:IN+1,:))**2  ! Smoothness indicator
+ZOMN1(:,IS+2:IN-1,:)  = 1./10. /  (ZEPS + ZBNEG1(:,IS+2:IN-1,:))**2             ! Non-normalized weight
+!
+! Second negative stencil, needs indices i-1, i, i+1
+ZFNEG2(:,IS+2:IN-1,:) = 1./6.  * (2.0*PSRC(:,IS+1:IN-2,:) + 5.0*PSRC(:,IS+2:IN-1,:) - 1.0*PSRC(:,IS+3:IN,:))  ! Flux
+ZBNEG2(:,IS+2:IN-1,:) = 13./12 * (    PSRC(:,IS+1:IN-2,:) - 2.0*PSRC(:,IS+2:IN-1,:) +     PSRC(:,IS+3:IN,:))**2 &
+      + 1./4   * (    PSRC(:,IS+1:IN-2,:) -                               PSRC(:,IS+3:IN,:))**2 ! Smoothness indicator
+ZOMN2(:,IS+2:IN-1,:)  = 3./5. /  (ZEPS + ZBNEG2(:,IS+2:IN-1,:))**2            ! Non-normalized weight
+!
+! Third negative stencil, needs indices i-2, i-1, i
+ZFNEG3(:,IS+2:IN-1,:) = 1./6   * (-1.0*PSRC(:,IS:IN-3,:) + 5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))  ! Flux
+ZBNEG3(:,IS+2:IN-1,:) = 13./12 * (  PSRC(:,IS:IN-3,:) - 2.0*PSRC(:,IS+1:IN-2,:) +     PSRC(:,IS+2:IN-1,:))**2 &
+      + 1./4   * (     PSRC(:,IS:IN-3,:) - 4.0*PSRC(:,IS+1:IN-2,:) + 3.0*PSRC(:,IS+2:IN-1,:))**2 ! Smoothness indicator
+ZOMN3(:,IS+2:IN-1,:)  = 3./10. / (ZEPS + ZBNEG3(:,IS+2:IN-1,:))**2             ! Non-normalized weight
+!
+! ----- Total flux -----
+!
+PR(:,IS+2:IN-1,:) = (ZOMP1(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+ZOMP2(:,IS+2:IN-1,:)+ZOMP3(:,IS+2:IN-1,:)) &
+           * ZFPOS1(:,IS+2:IN-1,:) + &
+                      ZOMP2(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+ZOMP2(:,IS+2:IN-1,:)+ZOMP3(:,IS+2:IN-1,:)) &
+           * ZFPOS2(:,IS+2:IN-1,:) + & 
+                      ZOMP3(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+ZOMP2(:,IS+2:IN-1,:)+ZOMP3(:,IS+2:IN-1,:)) &
+           * ZFPOS3(:,IS+2:IN-1,:)) &
+                    * (0.5+SIGN(0.5,PRVCT(:,IS+2:IN-1,:))) &
+                  + (ZOMN1(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+ZOMN3(:,IS+2:IN-1,:)) &
+           * ZFNEG1(:,IS+2:IN-1,:)  &
+                     + ZOMN2(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+ZOMN3(:,IS+2:IN-1,:)) &
+           * ZFNEG2(:,IS+2:IN-1,:)  &
+                     + ZOMN3(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+ZOMN3(:,IS+2:IN-1,:)) &
+           * ZFNEG3(:,IS+2:IN-1,:))  & 
+                    * (0.5-SIGN(0.5,PRVCT(:,IS+2:IN-1,:)))
 !
+!-------------------------------------------------------------------------------
+!*       1.2.   South border
+!               ---------------------
 !
-  ZFNEG2(:,IS+1:IN,:) = 1./6 * (2.0*PSRC(:,IS:IN-1,:) + &
-   5.0*PSRC(:,IS+1:IN,:) - 1.0*PSRC(:,IS+2:IN+1,:))
-  ZFNEG2(:,IN+1,:) = 0.5 * (PSRC(:,IN+1,:) + PSRC(:,IN,  :))
-  ZFNEG2(:,IS,  :) = 0.5 * (PSRC(:,IS,  :) + PSRC(:,IS-1,:))
-  ZFNEG2(:,IS-1,:) = 0.5 * (PSRC(:,IS-1,:) + TPHALO2%SOUTH(:,:))
+IF(LSOUTH_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! South border is physical -- IS+1,IS
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCY(1)) ! Y direction LBC type on south side
 ! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
+!
+ IF(LNORTH_ll()  .AND. .FALSE. ) THEN ! North border is physical 
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(:,IS+1,:) = 1./6. * (2.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS+1
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IN-1,:) - 7.0*PSRC(:,IN,:)   + 11.0*PSRC(:,IS-1,:)) ! Flux IS
+ ZBPOS1(:,IS+1,:) = 13./12. * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IN,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS+1
+ ZBPOS1(:,IS,:) = 13./12. * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IS-1,:))**2 & 
+      + 1./4    * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS
+ ZOMP1(:,IS:IS+1,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(:,IS+1,:) = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBPOS2(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IS
+ ZOMP2(:,IS:IS+1,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS:IS+1,:))**2  ! Non-normalized weight IS+1,IS
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(:,IS+1,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBNEG3(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IN,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS
+ ZOMN3(:,IS:IS+1,:) = 3./10. / (ZEPS + ZBNEG3(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+! 
+ ELSEIF(IS>3) THEN ! North boundary is proc border, with minimum 3 HALO points on sounth side
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(:,IS+1,:) = 1./6. * (2.0*PSRC(:,IS-2,:)   - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS+1
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-3,:) - 7.0*PSRC(:,IS-2,:)   + 11.0*PSRC(:,IS-1,:)) ! Flux IS
+ ZBPOS1(:,IS+1,:) = 13./12. * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS+1
+ ZBPOS1(:,IS,:) = 13./12. * (PSRC(:,IS-3,:) - 2.0*PSRC(:,IS-2,:) +     PSRC(:,IS-1,:))**2 & 
+      + 1./4    * (PSRC(:,IS-3,:) - 4.0*PSRC(:,IS-2,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS
+ ZOMP1(:,IS:IS+1,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(:,IS+1,:) = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IS-2,:) + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBPOS2(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IS-2,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IS
+ ZOMP2(:,IS:IS+1,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS:IS+1,:))**2  ! Non-normalized weight IS+1,IS
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(:,IS+1,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IS-2,:) + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBNEG3(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS
+ ZOMN3(:,IS:IS+1,:) = 3./10. / (ZEPS + ZBNEG3(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+! 
+ ELSE ! North boundary is proc border, with NHALO < 3 on south side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on south side'
+  CALL ABORT
+ ENDIF
+! 
+ ! Third positive stencil, needs indices i-1, i, i+1
+ ZFPOS3(:,IS+1,:) = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! Flux IS+1
+ ZFPOS3(:,IS,:)   = 1./6 * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) - PSRC(:,IS+1,:)) ! Flux IS
+ ZBPOS3(:,IS+1,:) = 13./12 * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 ! Smoothness indicator IS+1
+ ZBPOS3(:,IS,:)  = 13./12 * (    PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZOMP3(:,IS:IS+1,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(:,IS+1,:) = 1./6. * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) + 2.0*PSRC(:,IS+3,:)) ! Flux IS+1
+ ZFNEG1(:,IS,:)   = 1./6. * (11.0*PSRC(:,IS,:)   - 7.0*PSRC(:,IS+1,:) + 2.0*PSRC(:,IS+2,:)) ! Flux IS
+ ZBNEG1(:,IS+1,:) = 13./12. * (    PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2  ! Smoothness indicator IS+1
+ ZBNEG1(:,IS,:)   = 13./12. * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2  ! Smoothness indicator IS
+ ZOMN1(:,IS:IS+1,:) = 1./10. / (ZEPS + ZBNEG1(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(:,IS+1,:) = 1./6. * (2.0*PSRC(:,IS,:)   + 5.0*PSRC(:,IS+1,:) - 1.0*PSRC(:,IS+2,:)) ! Flux IS+1
+ ZFNEG2(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   - 1.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZBNEG2(:,IS+1,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (PSRC(:,IS,:) -                      PSRC(:,IS+2,:))**2 ! Smoothness indicator IS+1
+ ZBNEG2(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZOMN2(:,IS:IS+1,:) = 3./5. / (ZEPS + ZBNEG2(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IS:IS+1,:) = ( ZOMP1(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS1(:,IS:IS+1,:) &
+                       + ZOMP2(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS2(:,IS:IS+1,:) & 
+                       + ZOMP3(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS3(:,IS:IS+1,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IS:IS+1,:))) &
+                    + ( ZOMN1(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG1(:,IS:IS+1,:) &
+                       + ZOMN2(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG2(:,IS:IS+1,:) &
+                       + ZOMN3(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG3(:,IS:IS+1,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IS:IS+1,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IS
+    PR(:,IS,:) = PSRC(:,IS-1,:) * (0.5+SIGN(0.5,PRVCT(:,IS,:))) + &
+                 PSRC(:,IS,:)  * (0.5-SIGN(0.5,PRVCT(:,IS,:)))
+!
+!   ! WENO scheme order 3, IS+1
+    ZFPOS1(:,IS+1,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS-1,:)) ! First positive flux
+    ZFPOS2(:,IS+1,:) = 0.5 * ( PSRC(:,IS,:) + PSRC(:,IS+1,:)) ! Second positive flux
+    ZBPOS1(:,IS+1,:) = (PSRC(:,IS,:)   - PSRC(:,IS-1,:))**2 ! First positive smoothness indicator
+    ZBPOS2(:,IS+1,:) = (PSRC(:,IS+1,:) - PSRC(:,IS,:))**2  ! Second positive smoothness indicator
+!
+    ZFNEG1(:,IS+1,:) = 0.5 * (3.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! First negative flux
+    ZFNEG2(:,IS+1,:) = 0.5 * ( PSRC(:,IS+1,:) + PSRC(:,IS,:)) ! Second negative flux
+    ZBNEG1(:,IS+1,:) = (PSRC(:,IS+1,:) - PSRC(:,IS+2,:))**2 ! First negative smoothness indicator
+    ZBNEG2(:,IS+1,:) = (PSRC(:,IS,:)   - PSRC(:,IS+1,:))**2 ! Second negative smoothness indicator
+!
+    ZOMP1(:,IS+1,:) = 1./3. / (ZEPS + ZBPOS1(:,IS+1,:))**2 ! First positive non-normalized weight
+    ZOMP2(:,IS+1,:) = 2./3. / (ZEPS + ZBPOS2(:,IS+1,:))**2 ! Second positive non-normalized weight
+    ZOMN1(:,IS+1,:) = 1./3. / (ZEPS + ZBNEG1(:,IS+1,:))**2 ! First negative non-normalized weight
+    ZOMN2(:,IS+1,:) = 2./3. / (ZEPS + ZBNEG2(:,IS+1,:))**2 ! Second negative non-normalized weight
+! 
+    PR(:,IS+1,:) = (ZOMP2(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)) * ZFPOS2(:,IS+1,:) + &
+      (ZOMP1(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)) * ZFPOS1(:,IS+1,:))) &
+      *(0.5+SIGN(0.5,PRVCT(:,IS+1,:))) + &
+      (ZOMN2(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)) * ZFNEG2(:,IS+1,:) + &
+            (ZOMN1(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)) * ZFNEG1(:,IS+1,:))) &
+          *(0.5-SIGN(0.5,PRVCT(:,IS+1,:)))  ! Total flux
+!
+ END SELECT ! SELECT CASE (HLBCY(1)) ! Y direction LBC type on south side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! South border is proc border -- IS,IS-1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+!
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(:,IS+1,:) = 1./6. * (2.0*PSRC(:,IS-2,:)   - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS+1
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-3,:) - 7.0*PSRC(:,IS-2,:)   + 11.0*PSRC(:,IS-1,:)) ! Flux IS
+ ZBPOS1(:,IS+1,:) = 13./12. * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS+1
+ ZBPOS1(:,IS,:) = 13./12. * (PSRC(:,IS-3,:) - 2.0*PSRC(:,IS-2,:) +     PSRC(:,IS-1,:))**2 & 
+      + 1./4    * (PSRC(:,IS-3,:) - 4.0*PSRC(:,IS-2,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS
+ ZOMP1(:,IS:IS+1,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(:,IS+1,:) = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IS-2,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBPOS2(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IS-2,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IS
+ ZOMP2(:,IS:IS+1,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS:IS+1,:))**2  ! Non-normalized weight IS+1,IS
+! 
+ ! Third positive stencil, needs indices i-1, i, i+1
+ ZFPOS3(:,IS+1,:) = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! Flux IS+1
+ ZFPOS3(:,IS,:)   = 1./6 * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) - PSRC(:,IS+1,:)) ! Flux IS
+ ZBPOS3(:,IS+1,:) = 13./12 * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 ! Smoothness indicator IS+1
+ ZBPOS3(:,IS,:)  = 13./12 * (    PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZOMP3(:,IS:IS+1,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(:,IS+1,:) = 1./6. * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) + 2.0*PSRC(:,IS+3,:)) ! Flux IS+1
+ ZFNEG1(:,IS,:)   = 1./6. * (11.0*PSRC(:,IS,:)   - 7.0*PSRC(:,IS+1,:) + 2.0*PSRC(:,IS+2,:)) ! Flux IS
+ ZBNEG1(:,IS+1,:) = 13./12. * (    PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2  ! Smoothness indicator IS+1
+ ZBNEG1(:,IS,:)   = 13./12. * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2  ! Smoothness indicator IS
+ ZOMN1(:,IS:IS+1,:) = 1./10. / (ZEPS + ZBNEG1(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(:,IS+1,:) = 1./6. * (2.0*PSRC(:,IS,:)   + 5.0*PSRC(:,IS+1,:) - 1.0*PSRC(:,IS+2,:)) ! Flux IS+1
+ ZFNEG2(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   - 1.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZBNEG2(:,IS+1,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (PSRC(:,IS,:) -                      PSRC(:,IS+2,:))**2 ! Smoothness indicator IS+1
+ ZBNEG2(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZOMN2(:,IS:IS+1,:) = 3./5. / (ZEPS + ZBNEG2(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(:,IS+1,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IS-2,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS
+ ZBNEG3(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS+1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS
+ ZOMN3(:,IS:IS+1,:) = 3./10. / (ZEPS + ZBNEG3(:,IS:IS+1,:))**2 ! Non-normalized weight IS+1,IS
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IS:IS+1,:) = ( ZOMP1(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS1(:,IS:IS+1,:) &
+                       + ZOMP2(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS2(:,IS:IS+1,:) & 
+                       + ZOMP3(:,IS:IS+1,:)/(ZOMP1(:,IS:IS+1,:)+ZOMP2(:,IS:IS+1,:)+ZOMP3(:,IS:IS+1,:)) * ZFPOS3(:,IS:IS+1,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IS:IS+1,:))) &
+                    + ( ZOMN1(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG1(:,IS:IS+1,:) &
+                       + ZOMN2(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG2(:,IS:IS+1,:) &
+                       + ZOMN3(:,IS:IS+1,:)/(ZOMN1(:,IS:IS+1,:)+ZOMN2(:,IS:IS+1,:)+ZOMN3(:,IS:IS+1,:)) * ZFNEG3(:,IS:IS+1,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IS:IS+1,:)))
 !
-  ZFNEG3(:,IS+1:IN,:) = 1./6 * (-1.0*PSRC(:,IS-1:IN-2,:) + &
-   5.0*PSRC(:,IS:IN-1,:) + 2.0*PSRC(:,IS+1:IN,:))
-!
-! smoothness indicators for positive wind case
-!
-  ZBPOS1(:,IS+2:IN,:) = 13./12 * (PSRC(:,IS-1:IN-3,:) - 2.0*PSRC(:,IS:IN-2,:) + &
-   PSRC(:,IS+1:IN-1,:))**2 + 1./4 * (PSRC(:,IS-1:IN-3,:) - 4.0*PSRC(:,IS:IN-2,:) +&
-   3.0*PSRC(:,IS+1:IN-1,:))**2
-  ZBPOS1(:,IS+1,:) = 13./12 * (TPHALO2%SOUTH(:,:) - 2.0*PSRC(:,IS-1,:) + &
-   PSRC(:,IS,:))**2 + &
-   1./4 * (TPHALO2%SOUTH(:,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2
-  ZBPOS1(:,IN+1,:) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-  ZBPOS1(:,IS,  :) = (PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))**2
-  ZBPOS1(:,IS-1,:) = - 999. 
-!
-  ZBPOS2(:,IS+1:IN,:) = 13./12 * (PSRC(:,IS-1:IN-2,:) - 2.0*PSRC(:,IS:IN-1,:) + &
-   PSRC(:,IS+1:IN,:))**2 + 1./4 * (PSRC(:,IS-1:IN-2,:) - PSRC(:,IS+1:IN,:))**2
-  ZBPOS2(:,IN+1,:) = (PSRC(:,IN+1,:) - PSRC(:,IN,  :))**2
-  ZBPOS2(:,IS-1,:) = (PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))**2
-  ZBPOS2(:,IS,  :) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-!
-!
-  ZBPOS3(:,IS+1:IN,:) = 13./12 * (PSRC(:,IS:IN-1,:) - 2.0*PSRC(:,IS+1:IN,:) + &
-   PSRC(:,IS+2:IN+1,:))**2 + 1./4 * ( 3.0*PSRC(:,IS:IN-1,:) - 4.0*PSRC(:,IS+1:IN,:) + PSRC(:,IS+2:IN+1,:))**2
-!
-! smoothness indicators for negative wind case
-!
-  ZBNEG1(:,IS+1:IN-1,:) = 13./12 * (PSRC(:,IS+1:IN-1,:) - 2.0*PSRC(:,IS+2:IN,:) + &
-   PSRC(:,IS+3:IN+1,:))**2 + 1./4 * ( 3.0*PSRC(:,IS+1:IN-1,:) -                   &
-   4.0*PSRC(:,IS+2:IN,:) + PSRC(:,IS+3:IN+1,:))**2 
-  ZBNEG1(:,IN,       :) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) +           &
-   TPHALO2%NORTH(:,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))**2
-  ZBNEG1(:,IS-1,:) = (PSRC(:,IS-1,:) - PSRC(:,IS,:))**2
-  ZBNEG1(:,IS,  :) = (PSRC(:,IS,  :) - PSRC(:,IS+1,:))**2
-  ZBNEG1(:,IN+1,:) = (PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))**2
-!
-!
-  ZBNEG2(:,IS+1:IN,:) = 13./12 * (PSRC(:,IS:IN-1,:) - 2.0*PSRC(:,IS+1:IN,:) + &
-   PSRC(:,IS+2:IN+1,:))**2 + &
-   1./4 * (PSRC(:,IS:IN-1,:) - PSRC(:,IS+2:IN+1,:))**2
-  ZBNEG2(:,IN+1,:) = (PSRC(:,IN  ,:) - PSRC(:,IN+1,:))**2
-  ZBNEG2(:,IS,  :) = (PSRC(:,IS-1,:) - PSRC(:,IS,  :))**2
-  ZBNEG2(:,IS-1,:) = (TPHALO2%SOUTH(:,:) - PSRC(:,IS-1,:))**2
+ END IF ! NHALO
 !
+END IF ! IF(LSOUTH_ll()) 
 !
-  ZBNEG3(:,IS+1:IN,:) = 13./12 * (PSRC(:,IS-1:IN-2,:) - 2.0*PSRC(:,IS:IN-1,:) + &
-   PSRC(:,IS+1:IN,:))**2 + &
-   1./4 * ( PSRC(:,IS-1:IN-2,:) - 4.0*PSRC(:,IS:IN-1,:) + 3.0*PSRC(:,IS+1:IN,:))**2 
+!-------------------------------------------------------------------------------
+!*       1.3.   East border
+!               ---------------------
 !
-! WENO weights
+IF(LNORTH_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! North border is physical -- IN,IN+1
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCY(2)) ! Y direction LBC type on north side
+! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
 !
-  ZOMP1(:,IS+1:IN,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS+1:IN,:))**2
-  ZOMP2(:,IS+1:IN,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS+1:IN,:))**2
-  ZOMP3(:,IS+1:IN,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS+1:IN,:))**2
-  ZOMN1(:,IS+1:IN,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS+1:IN,:))**2
-  ZOMN2(:,IS+1:IN,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS+1:IN,:))**2
-  ZOMN3(:,IS+1:IN,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS+1:IN,:))**2
-!
-  ZOMP1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN+1,:))**2
-  ZOMP2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN+1,:))**2
-  ZOMN1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN+1,:))**2
-  ZOMN2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN+1,:))**2
-  ZOMP1(:,IS,  :) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS,  :))**2
-  ZOMP2(:,IS,  :) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS,  :))**2
-  ZOMN1(:,IS,  :) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS,  :))**2
-  ZOMN2(:,IS,  :) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS,  :))**2
-  ZOMP1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS-1,:))**2
-  ZOMP2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS-1,:))**2
-  ZOMN1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS-1,:))**2
-  ZOMN2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS-1,:))**2
-!
-! WENO fluxes (5th order)
-!
-  PR(:,IS+1:IN,:) = (ZOMP2(:,IS+1:IN,:)/(ZOMP1(:,IS+1:IN,:)+ZOMP2(:,IS+1:IN,:)+&
-                     ZOMP3(:,IS+1:IN,:)) * ZFPOS2(:,IS+1:IN,:)                 &
-                   + ZOMP1(:,IS+1:IN,:)/(ZOMP1(:,IS+1:IN,:)+ZOMP2(:,IS+1:IN,:)+&
-                     ZOMP3(:,IS+1:IN,:)) * ZFPOS1(:,IS+1:IN,:)                 &
-                   + ZOMP3(:,IS+1:IN,:)/(ZOMP1(:,IS+1:IN,:)+ZOMP2(:,IS+1:IN,:)+&
-                     ZOMP3(:,IS+1:IN,:)) * ZFPOS3(:,IS+1:IN,:)) *              &
-                   (0.5+SIGN(0.5,PRVCT(:,IS+1:IN,:)))                          &
-                  + (ZOMN2(:,IS+1:IN,:)/(ZOMN1(:,IS+1:IN,:)+ZOMN2(:,IS+1:IN,:)+&
-                     ZOMN3(:,IS+1:IN,:)) * ZFNEG2(:,IS+1:IN,:)                 &
-                   + ZOMN1(:,IS+1:IN,:)/(ZOMN1(:,IS+1:IN,:)+ZOMN2(:,IS+1:IN,:)+&
-                     ZOMN3(:,IS+1:IN,:)) * ZFNEG1(:,IS+1:IN,:)                 &
-                   + ZOMN3(:,IS+1:IN,:)/(ZOMN1(:,IS+1:IN,:)+ZOMN2(:,IS+1:IN,:)+&
-                     ZOMN3(:,IS+1:IN,:)) * ZFNEG3(:,IS+1:IN,:)) *              &
-                   (0.5-SIGN(0.5,PRVCT(:,IS+1:IN,:)))
-!
-! WENO fluxes (3rd order)
-!
-  PR(:,IS-1,:) =  (ZOMP2(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS2(:,IS-1,:)                                     &
-                 + ZOMP1(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS1(:,IS-1,:)) * (0.5+SIGN(0.5,PRVCT(:,IS-1,:)))  &
-                + (ZOMN2(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                  ZFNEG2(:,IS-1,:)                                     &
-                 + ZOMN1(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                  ZFNEG1(:,IS-1,:)) * (0.5-SIGN(0.5,PRVCT(:,IS-1,:)))
-!
-  PR(:,IS,  :) =  (ZOMP2(:,IS,  :)/(ZOMP1(:,IS,  :)+ZOMP2(:,IS,  :)) * &
-                  ZFPOS2(:,IS,  :)                                     &
-                 + ZOMP1(:,IS,  :)/(ZOMP1(:,IS,  :)+ZOMP2(:,IS,  :)) * &
-                  ZFPOS1(:,IS,  :)) * (0.5+SIGN(0.5,PRVCT(:,IS,  :)))  &
-                + (ZOMN2(:,IS,  :)/(ZOMN1(:,IS,  :)+ZOMN2(:,IS,  :)) * &
-                 ZFNEG2(:,IS,  :)                                      &
-                 + ZOMN1(:,IS,  :)/(ZOMN1(:,IS,  :)+ZOMN2(:,IS,  :)) * &
-                  ZFNEG1(:,IS,  :)) * (0.5-SIGN(0.5,PRVCT(:,IS,  :)))
-!
-  PR(:,IN+1,:) =  (ZOMP2(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:)) * &
-                  ZFPOS2(:,IN+1,:)                                     &
-                 + ZOMP1(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:)) * &
-                  ZFPOS1(:,IN+1,:)) * (0.5+SIGN(0.5,PRVCT(:,IN+1,:)))  &
-                + (ZOMN2(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                  ZFNEG2(:,IN+1,:)                                     &
-                 + ZOMN1(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                  ZFNEG1(:,IN+1,:)) * (0.5-SIGN(0.5,PRVCT(:,IN+1,:)))
-!
-!
-!       OPEN, WALL, NEST CASE IN THE Y DIRECTION
-!
-CASE ('OPEN','WALL','NEST')
-!
-  IS=IJB
-  IN=IJE
-!
-  IF(LSOUTH_ll()) THEN
-    PR(:,IS,:) = PSRC(:,IS-1,:) * (0.5+SIGN(0.5,PRVCT(:,IS,:))) + &
-                 PSRC(:,IS,:) * (0.5-SIGN(0.5,PRVCT(:,IS,:)))
-!
-    ZFPOS1(:,IS+1,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS-1,:))
-    ZFPOS2(:,IS+1,:) = 0.5 * (PSRC(:,IS,    :) + PSRC(:,IS+1,:))
-    ZBPOS1(:,IS+1,:) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-    ZBPOS2(:,IS+1,:) = (PSRC(:,IS+1,:) - PSRC(:,IS,  :))**2
-!
-    ZFNEG1(:,IS+1,:) = 0.5 * (3.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:))
-    ZFNEG2(:,IS+1,:) = 0.5 * (PSRC(:,IS+1,    :) + PSRC(:,IS,:))
-    ZBNEG1(:,IS+1,:) = (PSRC(:,IS+1,:) - PSRC(:,IS+2,:))**2
-    ZBNEG2(:,IS+1,:) = (PSRC(:,IS,  :) - PSRC(:,IS+1,:))**2
-!
-    ZOMP1(:,IS+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS+1,:))**2
-    ZOMP2(:,IS+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS+1,:))**2
-    ZOMN1(:,IS+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS+1,:))**2
-    ZOMN2(:,IS+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS+1,:))**2
-!
-    PR(:,IS+1,  :) =  (ZOMP2(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)) * &
-                   ZFPOS2(:,IS+1,:)                                        &
-                 + ZOMP1(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)) *     & 
-                   ZFPOS1(:,IS+1,:)) * (0.5+SIGN(0.5,PRVCT(:,IS+1,:)))     &
-                + (ZOMN2(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)) *     &
-                   ZFNEG2(:,IS+1,:)                                        &
-                 + ZOMN1(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)) *     &
-                   ZFNEG1(:,IS+1,:)) * (0.5-SIGN(0.5,PRVCT(:,IS+1,:)))
-!
-  ELSEIF(NHALO == 1) THEN
-    ZFPOS1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS-1, :) - TPHALO2%SOUTH(:,:))
-    ZFPOS2(:,IS,:) = 0.5 * (PSRC(:,IS-1,     :) + PSRC(:,IS,:))
-    ZBPOS1(:,IS,:) = (PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))**2
-    ZBPOS2(:,IS,:) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-!
-    ZFNEG1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS,  :) - PSRC(:,IS+1,:))
-    ZFNEG2(:,IS,:) = 0.5 * (PSRC(:,IS,      :) + PSRC(:,IS-1,:))
-    ZBNEG1(:,IS,:) = (PSRC(:,IS,  :) - PSRC(:,IS+1,:))**2
-    ZBNEG2(:,IS,:) = (PSRC(:,IS-1,:) - PSRC(:,IS,  :))**2
-!
-    ZOMP1(:,IS,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS,:))**2
-    ZOMP2(:,IS,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS,:))**2
-    ZOMN1(:,IS,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS,:))**2
-    ZOMN2(:,IS,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS,:))**2
-!
-    PR(:,IS,:) =  (ZOMP2(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS2(:,IS,:)   &
-                 + ZOMP1(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS1(:,IS,:)) *&
-                 (0.5+SIGN(0.5,PRVCT(:,IS,:)))  &
-                + (ZOMN2(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG2(:,IS,:)   &
-                 + ZOMN1(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG1(:,IS,:)) *&
-                 (0.5-SIGN(0.5,PRVCT(:,IS,:)))
-!
-    ZFPOS1(:,IS+1,:) = 1./6 * (2.0*TPHALO2%SOUTH(:,:) - 7.0*PSRC(:,IS-1,:) + &
-                       11.0*PSRC(:,IS,:))
-    ZFPOS2(:,IS+1,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) +      &
-                       2.0*PSRC(:,IS+1,:))
-    ZFPOS3(:,IS+1,:) = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) -       &
-                       1.0*PSRC(:,IS+2,:))
-!
-    ZBPOS1(:,IS+1,:) = 13./12 * (TPHALO2%SOUTH(:,:) - 2.0*PSRC(:,IS-1,:) +   &
-                       PSRC(:,IS,:))**2 + &
-     1./4 * (TPHALO2%SOUTH(:,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2
-    ZBPOS2(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +         &
-     PSRC(:,IS+1,:))**2 +     &
-     1./4 * (PSRC(:,IS-1,:) - PSRC(:,IS+1,:))**2
-    ZBPOS3(:,IS+1,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) +         &
-     PSRC(:,IS+2,:))**2 +     &
-     1./4 * ( 3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2
-!
-    ZFNEG1(:,IS+1,:) = 1./6 * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) +    &
-     2.0*PSRC(:,IS+3,:))
-    ZFNEG2(:,IS+1,:) = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) -       &
-     1.0*PSRC(:,IS+2,:))
-    ZFNEG3(:,IS+1,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) +      &
-     2.0*PSRC(:,IS+1,:))
-!
-    ZBNEG1(:,IS+1,:) = 13./12 * (PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) +       &
-     PSRC(:,IS+3,:))**2 +   &
-     1./4 * ( 3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2
-    ZBNEG2(:,IS+1,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) +         &
-     PSRC(:,IS+2,:))**2 +     &
-     1./4 * (PSRC(:,IS,:) - PSRC(:,IS+2,:))**2
-    ZBNEG3(:,IS+1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +         &
-     PSRC(:,IS+1,:))**2 +     &
-     1./4 * ( PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2
-!
-    ZOMP1(:,IS+1,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS+1,:))**2
-    ZOMP2(:,IS+1,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS+1,:))**2
-    ZOMP3(:,IS+1,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS+1,:))**2
-    ZOMN1(:,IS+1,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS+1,:))**2
-    ZOMN2(:,IS+1,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS+1,:))**2
-    ZOMN3(:,IS+1,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS+1,:))**2
-!
-    PR(:,IS+1,:) = (ZOMP2(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)+ &
-                   ZOMP3(:,IS+1,:)) * ZFPOS2(:,IS+1,:)    &
-                   + ZOMP1(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)+ &
-                   ZOMP3(:,IS+1,:)) * ZFPOS1(:,IS+1,:)   &
-                   + ZOMP3(:,IS+1,:)/(ZOMP1(:,IS+1,:)+ZOMP2(:,IS+1,:)+ &
-                   ZOMP3(:,IS+1,:)) * ZFPOS3(:,IS+1,:)) *&
-                   (0.5+SIGN(0.5,PRVCT(:,IS+1,:)))                     &
-                  + (ZOMN2(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)+ &
-                   ZOMN3(:,IS+1,:)) * ZFNEG2(:,IS+1,:)   &
-                   + ZOMN1(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)+ &
-                   ZOMN3(:,IS+1,:)) * ZFNEG1(:,IS+1,:)   &
-                   + ZOMN3(:,IS+1,:)/(ZOMN1(:,IS+1,:)+ZOMN2(:,IS+1,:)+ &
-                   ZOMN3(:,IS+1,:)) * ZFNEG3(:,IS+1,:)) *&
-                   (0.5-SIGN(0.5,PRVCT(:,IS+1,:)))
-!
-  ENDIF
-!
-  IF(LNORTH_ll()) THEN
-    PR(:,IN+1,:) = PSRC(:,IN,:) * (0.5+SIGN(0.5,PRVCT(:,IN+1,:))) + &
+ IF (LSOUTH_ll()  .AND. .FALSE. ) THEN ! South border is physical 
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN
+ ZFPOS3(:,IN+1,:) = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IS,:)) ! Flux IN+1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBPOS3(:,IN+1,:) = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2  ! Smoothness indicator IN+1
+ ZOMP3(:,IN:IN+1,:) = 3./10. / (ZEPS + ZBPOS3(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IS,:)) ! Flux IN
+ ZFNEG1(:,IN+1,:) = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IN+1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2  ! Smoothness indicator IN
+ ZBNEG1(:,IN+1,:) = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2  ! Smoothness indicator IN+1
+ ZOMN1(:,IN:IN+1,:) = 1./10. / (ZEPS + ZBNEG1(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZFNEG2(:,IN+1,:) = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IS,:)) ! Flux IN+1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBNEG2(:,IN+1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IN+1
+ ZOMN2(:,IN:IN+1,:) = 3./5. / (ZEPS + ZBNEG2(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ELSEIF(IN<=SIZE(PSRC,2)-3) THEN ! South boundary is proc border, with minimum 3 HALO points on north side
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN
+ ZFPOS3(:,IN+1,:) = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IN+2,:)) ! Flux IN+1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBPOS3(:,IN+1,:) = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN+1
+ ZOMP3(:,IN:IN+1,:) = 3./10. / (ZEPS + ZBPOS3(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IN+2,:)) ! Flux IN
+ ZFNEG1(:,IN+1,:) = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IN+2,:)   + 2.0*PSRC(:,IN+3,:)) ! Flux IN+1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN
+ ZBNEG1(:,IN+1,:) = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2  ! Smoothness indicator IN+1
+ ZOMN1(:,IN:IN+1,:) = 1./10. / (ZEPS + ZBNEG1(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZFNEG2(:,IN+1,:) = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IN+2,:)) ! Flux IN+1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBNEG2(:,IN+1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IN+2,:))**2  ! Smoothness indicator IN+1
+ ZOMN2(:,IN:IN+1,:) = 3./5. / (ZEPS + ZBNEG2(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ELSE ! South boundary is proc border, with NHALO < 3 on south side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on south side'
+  CALL ABORT
+ ENDIF
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + 11.0*PSRC(:,IN-1,:)) ! Flux IN
+ ZFPOS1(:,IN+1,:) = 1./6. * (2.0*PSRC(:,IN-2,:) - 7.0*PSRC(:,IN-1,:) + 11.0*PSRC(:,IN,:)) ! Flux IN+1
+ ZBPOS1(:,IN,:)   = 13./12. * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) +     PSRC(:,IN-1,:))**2 & 
+        + 1./4    * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2  ! Smoothness indicator IN
+ ZBPOS1(:,IN+1,:) = 13./12. * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 & 
+        + 1./4    * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2  ! Smoothness indicator IN+1
+ ZOMP1(:,IN:IN+1,:) = 1./10. / (ZEPS + ZBPOS1(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(:,IN,:)   = 1./6. * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN
+ ZFPOS2(:,IN+1,:) = 1./6. * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN+1
+ ZBPOS2(:,IN,:)   = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + PSRC(:,IN,:))**2 &
+      + 1./4   * (PSRC(:,IN-2,:) -                      PSRC(:,IN,:))**2 ! Smoothness indicator IN
+ ZBPOS2(:,IN+1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                   PSRC(:,IN+1,:))**2 ! Smoothness indicator IN+1
+ ZOMP2(:,IN:IN+1,:)  = 3./5. / (ZEPS + ZBPOS2(:,IN:IN+1,:))**2  ! Non-normalized weight IN,IN+1
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(:,IN,:)   = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN
+ ZFNEG3(:,IN+1,:) = 1./6 * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN+1
+ ZBNEG3(:,IN,:)   = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 &
+        + 1./4   * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2 ! Smoothness indicator IN
+ ZBNEG3(:,IN+1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IN+1,:))**2 &
+        + 1./4   * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IN+1,:))**2 ! Smoothness indicator IN+1
+ ZOMN3(:,IN:IN+1,:) = 3./10. / (ZEPS + ZBNEG3(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IN:IN+1,:) = ( ZOMP1(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS1(:,IN:IN+1,:) &
+                       + ZOMP2(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS2(:,IN:IN+1,:) & 
+                       + ZOMP3(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS3(:,IN:IN+1,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IN:IN+1,:))) &
+                    + ( ZOMN1(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG1(:,IN:IN+1,:) &
+                       + ZOMN2(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG2(:,IN:IN+1,:) &
+                       + ZOMN3(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG3(:,IN:IN+1,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IN:IN+1,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IN+1
+    PR(:,IN+1,:) = PSRC(:,IN,:)  * (0.5+SIGN(0.5,PRVCT(:,IN+1,:))) + &
                    PSRC(:,IN+1,:) * (0.5-SIGN(0.5,PRVCT(:,IN+1,:)))
 !
-    ZFPOS1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN-1,:) - PSRC(:,IN-2,:))
-    ZFPOS2(:,IN,:) = 0.5 * (PSRC(:,IN-1,    :) + PSRC(:,IN,  :))
-    ZBPOS1(:,IN,:) = (PSRC(:,IN-1,:) - PSRC(:,IN-2,:))**2
-    ZBPOS2(:,IN,:) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-!
-    ZFNEG1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) 
-    ZFNEG2(:,IN,:) = 0.5 * (PSRC(:,IN,    :) + PSRC(:,IN-1,:))
-    ZBNEG1(:,IN,:) = (PSRC(:,IN,  :) - PSRC(:,IN+1,:))**2
-    ZBNEG2(:,IN,:) = (PSRC(:,IN-1,:) - PSRC(:,IN,  :))**2   
-!
-    ZOMP1(:,IN,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN,:))**2
-    ZOMP2(:,IN,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN,:))**2
-    ZOMN1(:,IN,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN,:))**2
-    ZOMN2(:,IN,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN,:))**2
-!
-    PR(:,IN,:) =  (ZOMP2(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)) * ZFPOS2(:,IN,:)   &
-                 + ZOMP1(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)) * ZFPOS1(:,IN,:)) *&
-                 (0.5+SIGN(0.5,PRVCT(:,IN,:)))   &
-                + (ZOMN2(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)) * ZFNEG2(:,IN,:)   &
-                 + ZOMN1(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)) * ZFNEG1(:,IN,:)) *&
-                 (0.5-SIGN(0.5,PRVCT(:,IN,:)))
+!   ! WENO scheme order 3, IN
+    ZFPOS1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN-1,:) - PSRC(:,IN-2,:)) ! First positive flux
+    ZFPOS2(:,IN,:) = 0.5 * ( PSRC(:,IN-1,:) + PSRC(:,IN,:)) ! Second positive flux
+    ZBPOS1(:,IN,:) = (PSRC(:,IN-1,:) - PSRC(:,IN-2,:))**2 ! First positive smoothness indicator
+    ZBPOS2(:,IN,:) = (PSRC(:,IN,:)   - PSRC(:,IN-1,:))**2 ! Second positive smoothness indicator
+!
+    ZFNEG1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! First negative flux
+    ZFNEG2(:,IN,:) = 0.5 * ( PSRC(:,IN,:) + PSRC(:,IN-1,:)) ! Second negative flux
+    ZBNEG1(:,IN,:) = (PSRC(:,IN,:)   - PSRC(:,IN+1,:))**2 ! First negative smoothness indicator
+    ZBNEG2(:,IN,:) = (PSRC(:,IN-1,:) - PSRC(:,IN,:))**2  ! Second negative smoothness indicator
+!
+    ZOMP1(:,IN,:) = 1./3. / (ZEPS + ZBPOS1(:,IN,:))**2 ! First positive non-normalized weight
+    ZOMP2(:,IN,:) = 2./3. / (ZEPS + ZBPOS2(:,IN,:))**2 ! Second positive non-normalized weight
+    ZOMN1(:,IN,:) = 1./3. / (ZEPS + ZBNEG1(:,IN,:))**2 ! First negative non-normalized weight
+    ZOMN2(:,IN,:) = 2./3. / (ZEPS + ZBNEG2(:,IN,:))**2 ! Second negative non-normalized weight
+! 
+    PR(:,IN,:) = (ZOMP2(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:))*ZFPOS2(:,IN,:) + &
+                 (ZOMP1(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:))*ZFPOS1(:,IN,:))) &
+     *(0.5+SIGN(0.5,PRVCT(:,IN,:))) + &
+     (ZOMN2(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:))*ZFNEG2(:,IN,:) + &
+     (ZOMN1(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:))*ZFNEG1(:,IN,:))) &
+     *(0.5-SIGN(0.5,PRVCT(:,IN,:)))  ! Total flux
+!
+ END SELECT ! SELECT CASE (HLBCX(2)) ! X direction LBC type on right side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! North border is proc border -- IN,IN+1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >= 3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+! 
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-3, i-2, i-1 
+ ZFPOS1(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + 11.0*PSRC(:,IN-1,:)) ! Flux IN
+ ZFPOS1(:,IN+1,:) = 1./6. * (2.0*PSRC(:,IN-2,:) - 7.0*PSRC(:,IN-1,:) + 11.0*PSRC(:,IN,:)) ! Flux IN+1
+ ZBPOS1(:,IN,:)   = 13./12. * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) +     PSRC(:,IN-1,:))**2 & 
+        + 1./4    * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2  ! Smoothness indicator IN
+ ZBPOS1(:,IN+1,:) = 13./12. * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 & 
+        + 1./4    * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2  ! Smoothness indicator IN+1
+ ZOMP1(:,IN:IN+1,:) = 1./10. / (ZEPS + ZBPOS1(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Second positive stencil, needs indices i-2, i-1, i
+ ZFPOS2(:,IN,:)   = 1./6. * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN
+ ZFPOS2(:,IN+1,:) = 1./6. * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN+1
+ ZBPOS2(:,IN,:)   = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + PSRC(:,IN,:))**2 &
+      + 1./4   * (PSRC(:,IN-2,:) -                      PSRC(:,IN,:))**2 ! Smoothness indicator IN
+ ZBPOS2(:,IN+1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                   PSRC(:,IN+1,:))**2 ! Smoothness indicator IN+1
+ ZOMP2(:,IN:IN+1,:)  = 3./5. / (ZEPS + ZBPOS2(:,IN:IN+1,:))**2  ! Non-normalized weight IN,IN+1
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN
+ ZFPOS3(:,IN+1,:) = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IN+2,:)) ! Flux IN+1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBPOS3(:,IN+1,:) = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN+1
+ ZOMP3(:,IN:IN+1,:) = 3./10. / (ZEPS + ZBPOS3(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i, i+1, i+2
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IN+2,:)) ! Flux IN
+ ZFNEG1(:,IN+1,:) = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IN+2,:)   + 2.0*PSRC(:,IN+3,:)) ! Flux IN+1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN
+ ZBNEG1(:,IN+1,:) = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2  ! Smoothness indicator IN+1
+ ZOMN1(:,IN:IN+1,:) = 1./10. / (ZEPS + ZBNEG1(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Second negative stencil, needs indices i-1, i, i+1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZFNEG2(:,IN+1,:) = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IN+2,:)) ! Flux IN+1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZBNEG2(:,IN+1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IN+2,:))**2  ! Smoothness indicator IN+1
+ ZOMN2(:,IN:IN+1,:) = 3./5. / (ZEPS + ZBNEG2(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! Third negative stencil, needs indices i-2, i-1, i
+ ZFNEG3(:,IN,:)   = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN
+ ZFNEG3(:,IN+1,:) = 1./6 * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN+1
+ ZBNEG3(:,IN,:)   = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 &
+        + 1./4   * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2 ! Smoothness indicator IN
+ ZBNEG3(:,IN+1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IN+1,:))**2 &
+        + 1./4   * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IN+1,:))**2 ! Smoothness indicator IN+1
+ ZOMN3(:,IN:IN+1,:) = 3./10. / (ZEPS + ZBNEG3(:,IN:IN+1,:))**2 ! Non-normalized weight IN,IN+1
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IN:IN+1,:) = ( ZOMP1(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS1(:,IN:IN+1,:) &
+                       + ZOMP2(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS2(:,IN:IN+1,:) & 
+                       + ZOMP3(:,IN:IN+1,:)/(ZOMP1(:,IN:IN+1,:)+ZOMP2(:,IN:IN+1,:)+ZOMP3(:,IN:IN+1,:)) * ZFPOS3(:,IN:IN+1,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IN:IN+1,:))) &
+                    + ( ZOMN1(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG1(:,IN:IN+1,:) &
+                       + ZOMN2(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG2(:,IN:IN+1,:) &
+                       + ZOMN3(:,IN:IN+1,:)/(ZOMN1(:,IN:IN+1,:)+ZOMN2(:,IN:IN+1,:)+ZOMN3(:,IN:IN+1,:)) * ZFNEG3(:,IN:IN+1,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IN:IN+1,:)))
+!
+ END IF ! NHALO
+!
+END IF ! IF(LNORTH_ll()) 
+!-------------------------------------------------------------------------------
 !
-  ELSEIF(NHALO == 1) THEN
-    ZFPOS1(:,IN+1,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN-1,:))
-    ZFPOS2(:,IN+1,:) = 0.5 * (PSRC(:,IN,    :) + PSRC(:,IN+1,:))
-    ZBPOS1(:,IN+1,:) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-    ZBPOS2(:,IN+1,:) = (PSRC(:,IN+1,:) - PSRC(:,IN,  :))**2
-!
-    ZFNEG1(:,IN+1,:) = 0.5 * (3.0*PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))
-    ZFNEG2(:,IN+1,:) = 0.5 * (PSRC(:,IN+1,    :) + PSRC(:,IN,  :))
-    ZBNEG1(:,IN+1,:) = (PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))**2
-    ZBNEG2(:,IN+1,:) = (PSRC(:,IN  ,:) - PSRC(:,IN+1,:))**2
-!
-    ZOMP1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN+1,:))**2
-    ZOMP2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN+1,:))**2
-    ZOMN1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN+1,:))**2
-    ZOMN2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN+1,:))**2
-!
-    PR(:,IN+1,:) =  (ZOMP2(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:))*&
-                   ZFPOS2(:,IN+1,:)                                    &
-                 + ZOMP1(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:)) * &
-                   ZFPOS1(:,IN+1,:)) * (0.5+SIGN(0.5,PRVCT(:,IN+1,:))) &
-                + (ZOMN2(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                   ZFNEG2(:,IN+1,:)                                    &
-                 + ZOMN1(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                   ZFNEG1(:,IN+1,:)) * (0.5-SIGN(0.5,PRVCT(:,IN+1,:)))
-!
-    ZFPOS1(:,IN,:) = 1./6 * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + &
-     11.0*PSRC(:,IN-1,:))
-    ZFPOS2(:,IN,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + &
-     2.0*PSRC(:,IN,:))
-    ZFPOS3(:,IN,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - &
-     1.0*PSRC(:,IN+1,:))
-!
-    ZBPOS1(:,IN,:) = 13./12 * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) + &
-    PSRC(:,IN-1,:))**2 + &
-     1./4 * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2
-    ZBPOS2(:,IN,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + &
-    PSRC(:,IN,:))**2 + &
-     1./4 * (PSRC(:,IN-2,:) - PSRC(:,IN,:))**2
-    ZBPOS3(:,IN,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + &
-    PSRC(:,IN+1,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2
-!
-    ZFNEG1(:,IN,:) = 1./6 * (11.0*PSRC(:,IN,:) - 7.0*PSRC(:,IN+1,:) + &
-    2.0*TPHALO2%NORTH(:,:))
-    ZFNEG2(:,IN,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - &
-    1.0*PSRC(:,IN+1,:))
-    ZFNEG3(:,IN,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + &
-    2.0*PSRC(:,IN,:))
-!
-    ZBNEG1(:,IN,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + &
-    TPHALO2%NORTH(:,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))**2
-    ZBNEG2(:,IN,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + &
-    PSRC(:,IN+1,:))**2 + &
-     1./4 * (PSRC(:,IN-1,:) - PSRC(:,IN+1,:))**2
-    ZBNEG3(:,IN,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +&
-    PSRC(:,IN,:))**2 + &
-     1./4 * ( PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2
-!
-    ZOMP1(:,IN,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IN,:))**2
-    ZOMP2(:,IN,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IN,:))**2
-    ZOMP3(:,IN,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IN,:))**2
-    ZOMN1(:,IN,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IN,:))**2
-    ZOMN2(:,IN,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IN,:))**2
-    ZOMN3(:,IN,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IN,:))**2
-!
-    PR(:,IN,:) = (ZOMP2(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)+ZOMP3(:,IN,:)) * &
-    ZFPOS2(:,IN,:)     &
-    + ZOMP1(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)+ZOMP3(:,IN,:)) * ZFPOS1(:,IN,:)  &
-    + ZOMP3(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)+ZOMP3(:,IN,:)) * ZFPOS3(:,IN,:)) &
-    * (0.5+SIGN(0.5,PRVCT(:,IN,:))) &
-    + (ZOMN2(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)+ZOMN3(:,IN,:)) * ZFNEG2(:,IN,:)  &
-    + ZOMN1(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)+ZOMN3(:,IN,:)) * ZFNEG1(:,IN,:)  &
-    + ZOMN3(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)+ZOMN3(:,IN,:)) * ZFNEG3(:,IN,:)) &
-    * (0.5-SIGN(0.5,PRVCT(:,IN,:)))
-!
-  ENDIF
-!
-!        USE A FIFTH ORDER UPSTREAM WENO SCHEME ELSEWHERE (IS+2 --> IN-1)
-!
-  ZFPOS1(:,IS+2:IN-1,:) = 1./6 * (2.0*PSRC(:,IS-1:IN-4,:) - &
-  7.0*PSRC(:,IS:IN-3,  :) + 11.0*PSRC(:,IS+1:IN-2,:))
-  ZFPOS2(:,IS+2:IN-1,:) = 1./6 * (-1.0*PSRC(:,IS:IN-3, :) + &
-  5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1, :))
-  ZFPOS3(:,IS+2:IN-1,:) = 1./6 * (2.0*PSRC(:,IS+1:IN-2,:) + &
-  5.0*PSRC(:,IS+2:IN-1,:) - 1.0*PSRC(:,IS+3:IN,   :))
-!
-  ZBPOS1(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS-1:IN-4,:) - &
-  2.0*PSRC(:,IS:IN-3,:) + PSRC(:,IS+1:IN-2,:))**2 + &
-   1./4 * (PSRC(:,IS-1:IN-4,:) - 4.0*PSRC(:,IS:IN-3,:) + &
-   3.0*PSRC(:,IS+1:IN-2,:))**2
-  ZBPOS2(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS:IN-3,:) - &
-  2.0*PSRC(:,IS+1:IN-2,:) + PSRC(:,IS+2:IN-1,:))**2 + &
-   1./4 * (PSRC(:,IS:IN-3,:) - PSRC(:,IS+2:IN-1,:))**2
-  ZBPOS3(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS+1:IN-2,:) - &
-  2.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS+1:IN-2,:) - 4.0*PSRC(:,IS+2:IN-1,:) +&
-   PSRC(:,IS+3:IN,:))**2
-!
-  ZFNEG1(:,IS+2:IN-1,:) = 1./6 * (11.0*PSRC(:,IS+2:IN-1,:) - &
-  7.0*PSRC(:,IS+3:IN,:) + 2.0*PSRC(:,IS+4:IN+1,:))
-  ZFNEG2(:,IS+2:IN-1,:) = 1./6 * (2.0*PSRC(:,IS+1:IN-2,:) + &
-  5.0*PSRC(:,IS+2:IN-1,:) - 1.0*PSRC(:,IS+3:IN,:))
-  ZFNEG3(:,IS+2:IN-1,:) = 1./6 * (-1.0*PSRC(:,IS:IN-3,:) + &
-  5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))
-!
-  ZBNEG1(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS+2:IN-1,:) - &
-  2.0*PSRC(:,IS+3:IN,:) + PSRC(:,IS+4:IN+1,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS+2:IN-1,:) - 4.0*PSRC(:,IS+3:IN,:) + &
-   PSRC(:,IS+4:IN+1,:))**2
-  ZBNEG2(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS+1:IN-2,:) - &
-  2.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 + &
-  1./4 * (PSRC(:,IS+1:IN-2,:) - PSRC(:,IS+3:IN,:))**2
-  ZBNEG3(:,IS+2:IN-1,:) = 13./12 * (PSRC(:,IS:IN-3,:) - &
-  2.0*PSRC(:,IS+1:IN-2,:) + PSRC(:,IS+2:IN-1,:))**2 + &
-  1./4 * ( PSRC(:,IS:IN-3,:) - 4.0*PSRC(:,IS+1:IN-2,:) + &
-  3.0*PSRC(:,IS+2:IN-1,:))**2
-!
-  ZOMP1(:,IS+2:IN-1,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS+2:IN-1,:))**2
-  ZOMP2(:,IS+2:IN-1,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS+2:IN-1,:))**2
-  ZOMP3(:,IS+2:IN-1,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS+2:IN-1,:))**2
-  ZOMN1(:,IS+2:IN-1,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS+2:IN-1,:))**2
-  ZOMN2(:,IS+2:IN-1,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS+2:IN-1,:))**2
-  ZOMN3(:,IS+2:IN-1,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS+2:IN-1,:))**2
-!
-    PR(:,IS+2:IN-1,:) = (ZOMP2(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+&
-     ZOMP2(:,IS+2:IN-1,:)+ZOMP3(:,IS+2:IN-1,:)) * ZFPOS2(:,IS+2:IN-1,:)  &
-     + ZOMP1(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+&
-     ZOMP2(:,IS+2:IN-1,:)+ZOMP3(:,IS+2:IN-1,:)) * ZFPOS1(:,IS+2:IN-1,:)  &
-     + ZOMP3(:,IS+2:IN-1,:)/(ZOMP1(:,IS+2:IN-1,:)+ZOMP2(:,IS+2:IN-1,:)+ &
-     ZOMP3(:,IS+2:IN-1,:)) * ZFPOS3(:,IS+2:IN-1,:)) &
-     * (0.5+SIGN(0.5,PRVCT(:,IS+2:IN-1,:))) &
-     + (ZOMN2(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+ &
-     ZOMN3(:,IS+2:IN-1,:)) * ZFNEG2(:,IS+2:IN-1,:)                 &
-     + ZOMN1(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+ &
-     ZOMN3(:,IS+2:IN-1,:)) * ZFNEG1(:,IS+2:IN-1,:)                     &
-     + ZOMN3(:,IS+2:IN-1,:)/(ZOMN1(:,IS+2:IN-1,:)+ZOMN2(:,IS+2:IN-1,:)+&
-     ZOMN3(:,IS+2:IN-1,:)) * ZFNEG3(:,IS+2:IN-1,:)) &
-     * (0.5-SIGN(0.5,PRVCT(:,IS+2:IN-1,:)))
-!
-END SELECT
-!
-PR = PR * PRVCT
+PR = PR * PRVCT ! Add contravariant flux
 !
 END SUBROUTINE ADVEC_WENO_K_3_MY
 !
 !-------------------------------------------------------------------------------
 !
 !     #############################################################
-      SUBROUTINE ADVEC_WENO_K_3_VY(HLBCY, PSRC, PRVCT, PR, TPHALO2)
+      SUBROUTINE ADVEC_WENO_K_3_VY(HLBCY, PSRC, PRVCT, PR)
 !     #############################################################
 !!
 !!**** Computes PRVCT * PVT. Upstream fluxes of V in Y direction.  
@@ -1963,13 +2086,16 @@ END SUBROUTINE ADVEC_WENO_K_3_MY
 !!
 !!    MODIFICATIONS
 !!    -------------
+!! T. Lunet 02/10/2014:  Correction of periodic boudary conditions
+!!       Change of structure in order to adapt WENO to NHALOK
+!!       Suppression of second layer HALO pointers
+!!       Complete code documentation
 !!
 !-------------------------------------------------------------------------------
 !
 USE MODE_ll
 USE MODD_LUNIT
 USE MODD_CONF
-USE MODD_ARGSLIST_ll, ONLY : HALO2LIST_ll
 !
 IMPLICIT NONE
 !
@@ -1982,13 +2108,12 @@ REAL, DIMENSION(:,:,:), INTENT(IN)  :: PRVCT ! contrav. comp. on MASS GRID
 !
 ! output source term
 REAL, DIMENSION(:,:,:), INTENT(INOUT) :: PR
-TYPE(HALO2_ll), OPTIONAL, POINTER :: TPHALO2      ! halo2 for the field at t
 !
 !*       0.2   Declarations of local variables :
 !
 INTEGER :: IIB,IJB    ! Begining useful area in x,y,z directions
 INTEGER :: IIE,IJE    ! End useful area in x,y,z directions
-INTEGER::  IS,IN   ! Coordinate of third order diffusion area
+INTEGER::  IS,IN    ! Physical boundary index
 !
 INTEGER:: ILUOUT,IRESP   ! for prints
 !
@@ -1997,7 +2122,7 @@ INTEGER:: ILUOUT,IRESP   ! for prints
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
+!
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -2011,15 +2136,9 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)) :: ZOMN1, ZOMN2, ZOMN3
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
-    REAL, PARAMETER :: ZEPS = 1.0E-15
+! EPSILON for weno weights calculation
+! 
+REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !----------------------------------------------------------------------------
 !
@@ -2055,468 +2174,556 @@ ZOMN2  = 0.0
 ZOMN3  = 0.0
 !
 !-------------------------------------------------------------------------------
+!-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
+IS=IJB
+IN=IJE
 !
-SELECT CASE ( HLBCY(1) ) ! Y direction LBC type: (1) for left side
-!
-!*       1.1    CYCLIC CASE IN THE Y DIRECTION:
-!
-CASE ('CYCL')          ! In that case one must have HLBCX(1) == HLBCX(2)
-!
-  IF(NHALO == 1) THEN
-    IS=IJB
-    IN=IJE
-  ELSE
-      CALL FMLOOK_ll(CLUOUT0,CLUOUT0,ILUOUT,IRESP)
-      WRITE(ILUOUT,*) 'ERROR : 4th order advection in CYCLic case '
-      WRITE(ILUOUT,*) 'cannot be used with NHALO=2'
-      CALL ABORT
-      STOP
-  END IF
-!
-! Same explanation than for the subroutine ADVEC_WENO_K_3_UX
-!
-! intermediate fluxes for positive wind case
-!
-  ZFPOS1(:,IS+1:IN-1,:) = 1./6 * (2.0*PSRC(:,IS-1:IN-3,:) - 7.0*PSRC(:,IS:IN-2,:) +&
-  11.0*PSRC(:,IS+1:IN-1,:))
-  ZFPOS1(:,IS,       :) = 1./6 * (2.0*TPHALO2%SOUTH(:,:)  - 7.0*PSRC(:,IS-1,   :) +&
-  11.0*PSRC(:,IS,       :))
-  ZFPOS1(:,IS-1,:) = 0.5 * (3.0*PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))
-  ZFPOS1(:,IN,  :) = 0.5 * (3.0*PSRC(:,IN,  :) - PSRC(:,IN-1,:))
-  ZFPOS1(:,IN+1,:) = 0.5 * (3.0*PSRC(:,IN+1,:) - PSRC(:,IN,  :))
-!
-!  
-  ZFPOS2(:,IS:IN-1,:) = 1./6 * (-1.0*PSRC(:,IS-1:IN-2,:) + 5.0*PSRC(:,IS:IN-1,:) +&
-  2.0*PSRC(:,IS+1:IN,:))
-  ZFPOS2(:,IS-1,:) = 0.5 * (PSRC(:,IS-1,:) + PSRC(:,IS,  :))
-  ZFPOS2(:,IN,  :) = 0.5 * (PSRC(:,IN,  :) + PSRC(:,IN+1,:)) 
-  ZFPOS2(:,IN+1,:) = 0.5 * (PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))
-!
-!
-  ZFPOS3(:,IS:IN-1,:) = 1./6 * (2.0*PSRC(:,IS:IN-1,:) + 5.0*PSRC(:,IS+1:IN,:) - &
-  1.0*PSRC(:,IS+2:IN+1,:))
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IS+1 -> IN-2
+! Computation at the mass point on Vgrid v(i+1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-! intermediate flux for negative wind case
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-2, i-1, i
+ZFPOS1(:,IS+1:IN-2,:) = 1./6.   * (2.0*PSRC(:,IS-1:IN-4,:) - 7.0*PSRC(:,IS:IN-3,:) + 11.0*PSRC(:,IS+1:IN-2,:))   ! Flux
+ZBPOS1(:,IS+1:IN-2,:) = 13./12. * (    PSRC(:,IS-1:IN-4,:) - 2.0*PSRC(:,IS:IN-3,:) +      PSRC(:,IS+1:IN-2,:))**2 & 
+      + 1./4    * (    PSRC(:,IS-1:IN-4,:) - 4.0*PSRC(:,IS:IN-3,:) + 3.0* PSRC(:,IS+1:IN-2,:))**2  ! Smoothness indicator
+ZOMP1(:,IS+1:IN-2,:)  = 1./10. /  (ZEPS + ZBPOS1(:,IS+1:IN-2,:))**2             ! Non-normalized weight
+!
+! Second positive stencil, needs indices i-1, i, i+1
+ZFPOS2(:,IS+1:IN-2,:) = 1./6.  * (-1.0*PSRC(:,IS:IN-3,:) + 5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))  ! Flux
+ZBPOS2(:,IS+1:IN-2,:) = 13./12 * (     PSRC(:,IS:IN-3,:) - 2.0*PSRC(:,IS+1:IN-2,:) +     PSRC(:,IS+2:IN-1,:))**2 &
+      + 1./4   * (     PSRC(:,IS:IN-3,:) -                               PSRC(:,IS+2:IN-1,:))**2 ! Smoothness indicator
+ZOMP2(:,IS+1:IN-2,:)  = 3./5. /  (ZEPS + ZBPOS2(:,IS+1:IN-2,:))**2             ! Non-normalized weight
+!
+! Third positive stencil, needs indices i, i+1, i+2
+ZFPOS3(:,IS+1:IN-2,:) = 1./6   * (2.0*PSRC(:,IS+1:IN-2,:) + 5.0*PSRC(:,IS+2:IN-1,:) - PSRC(:,IS+3:IN,:))  ! Flux
+ZBPOS3(:,IS+1:IN-2,:) = 13./12 * ( PSRC(:,IS+1:IN-2,:) - 2.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS+1:IN-2,:) - 4.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 ! Smoothness indicator
+ZOMP3(:,IS+1:IN-2,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS+1:IN-2,:))**2           ! Non-normalized weight
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i+1, i+2, i+3
+ZFNEG1(:,IS+1:IN-2,:) = 1./6.   * (11.0*PSRC(:,IS+2:IN-1,:) - 7.0*PSRC(:,IS+3:IN,:) + 2.0*PSRC(:,IS+4:IN+1,:))   ! Flux
+ZBNEG1(:,IS+1:IN-2,:) = 13./12. * (     PSRC(:,IS+2:IN-1,:) - 2.0*PSRC(:,IS+3:IN,:) +     PSRC(:,IS+4:IN+1,:))**2 & 
+      + 1./4    * (3.0* PSRC(:,IS+2:IN-1,:) - 4.0*PSRC(:,IS+3:IN,:) +     PSRC(:,IS+4:IN+1,:))**2  ! Smoothness indicator
+ZOMN1(:,IS+1:IN-2,:)  = 1./10. /  (ZEPS + ZBNEG1(:,IS+1:IN-2,:))**2             ! Non-normalized weight
+!
+! Second negative stencil, needs indices i, i+1, i+2
+ZFNEG2(:,IS+1:IN-2,:) = 1./6.  * (2.0*PSRC(:,IS+1:IN-2,:) + 5.0*PSRC(:,IS+2:IN-1,:) - 1.0*PSRC(:,IS+3:IN,:))  ! Flux
+ZBNEG2(:,IS+1:IN-2,:) = 13./12 * (    PSRC(:,IS+1:IN-2,:) - 2.0*PSRC(:,IS+2:IN-1,:) +     PSRC(:,IS+3:IN,:))**2 &
+      + 1./4   * (    PSRC(:,IS+1:IN-2,:) -                               PSRC(:,IS+3:IN,:))**2 ! Smoothness indicator
+ZOMN2(:,IS+1:IN-2,:)  = 3./5. /  (ZEPS + ZBNEG2(:,IS+1:IN-2,:))**2            ! Non-normalized weight
+!
+! Third negative stencil, needs indices i-1, i, i+1
+ZFNEG3(:,IS+1:IN-2,:) = 1./6   * (-1.0*PSRC(:,IS:IN-3,:) + 5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))  ! Flux
+ZBNEG3(:,IS+1:IN-2,:) = 13./12 * (  PSRC(:,IS:IN-3,:) - 2.0*PSRC(:,IS+1:IN-2,:) +     PSRC(:,IS+2:IN-1,:))**2 &
+      + 1./4   * (     PSRC(:,IS:IN-3,:) - 4.0*PSRC(:,IS+1:IN-2,:) + 3.0*PSRC(:,IS+2:IN-1,:))**2 ! Smoothness indicator
+ZOMN3(:,IS+1:IN-2,:)  = 3./10. / (ZEPS + ZBNEG3(:,IS+1:IN-2,:))**2             ! Non-normalized weight
+!
+!
+! ----- Total flux -----
+!
+PR(:,IS+1:IN-2,:) = (ZOMP1(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+ZOMP2(:,IS+1:IN-2,:)+ZOMP3(:,IS+1:IN-2,:)) &
+           * ZFPOS1(:,IS+1:IN-2,:) + &
+                      ZOMP2(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+ZOMP2(:,IS+1:IN-2,:)+ZOMP3(:,IS+1:IN-2,:)) &
+           * ZFPOS2(:,IS+1:IN-2,:) + & 
+                      ZOMP3(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+ZOMP2(:,IS+1:IN-2,:)+ZOMP3(:,IS+1:IN-2,:)) &
+           * ZFPOS3(:,IS+1:IN-2,:)) &
+                    * (0.5+SIGN(0.5,PRVCT(:,IS+1:IN-2,:))) &
+                  + (ZOMN1(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+ZOMN3(:,IS+1:IN-2,:)) &
+           * ZFNEG1(:,IS+1:IN-2,:)  &
+                     + ZOMN2(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+ZOMN3(:,IS+1:IN-2,:)) &
+           * ZFNEG2(:,IS+1:IN-2,:)  &
+                     + ZOMN3(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+ZOMN3(:,IS+1:IN-2,:)) &
+           * ZFNEG3(:,IS+1:IN-2,:))  & 
+                    * (0.5-SIGN(0.5,PRVCT(:,IS+1:IN-2,:)))
 !
-  ZFNEG1(:,IS:IN-2,:) = 1./6 * (11.0*PSRC(:,IS+1:IN-1,:) - 7.0*PSRC(:,IS+2:IN,:) +&
-  2.0*PSRC(:,IS+3:IN+1,:))
-  ZFNEG1(:,IN-1,   :) = 1./6 * (11.0*PSRC(:,IN,       :) - 7.0*PSRC(:,IN+1,   :) +&
-  2.0*TPHALO2%NORTH(:,:))
-  ZFNEG1(:,IS-1,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS+1,:))
-  ZFNEG1(:,IN+1,:) = - 999.
-  ZFNEG1(:,IN,  :) = 0.5 * (3.0*PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))
+!-------------------------------------------------------------------------------
+!*       1.2.   South border
+!               ---------------------
 !
+IF(LSOUTH_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! South border is physical -- IS,IS-1
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCY(1)) ! Y direction LBC type on south side
+! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
+!
+ IF(LNORTH_ll()  .AND. .FALSE. ) THEN ! North border is physical 
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS
+ ZFPOS1(:,IS-1,:) = 1./6. * (2.0*PSRC(:,IN-1,:) - 7.0*PSRC(:,IN,:)   + 11.0*PSRC(:,IS-1,:)) ! Flux IS-1
+ ZBPOS1(:,IS,:)   = 13./12. * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IN,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS
+ ZBPOS1(:,IS-1,:) = 13./12. * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IS-1,:))**2 & 
+        + 1./4    * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS-1
+ ZOMP1(:,IS-1:IS,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFPOS2(:,IS-1,:) = 1./6.* (-1.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBPOS2(:,IS-1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IS-1
+ ZOMP2(:,IS-1:IS,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS-1:IS,:))**2  ! Non-normalized weight IS,IS-1
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFNEG3(:,IS-1,:) = 1./6 * (-1.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBNEG3(:,IS-1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IN,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS-1
+ ZOMN3(:,IS-1:IS,:) = 3./10. / (ZEPS + ZBNEG3(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+! 
+ ELSEIF(IS>3) THEN ! North boundary is proc border, with minimum 3 HALO points on south side
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-2,:)   - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS
+ ZFPOS1(:,IS-1,:) = 1./6. * (2.0*PSRC(:,IS+3,:) - 7.0*PSRC(:,IS-2,:)   + 11.0*PSRC(:,IS-1,:)) ! Flux IS-1
+ ZBPOS1(:,IS,:)   = 13./12. * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS
+ ZBPOS1(:,IS-1,:) = 13./12. * (PSRC(:,IS-3,:) - 2.0*PSRC(:,IS-2,:) +     PSRC(:,IS-1,:))**2 & 
+        + 1./4    * (PSRC(:,IS-3,:) - 4.0*PSRC(:,IS-2,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS-1
+ ZOMP1(:,IS-1:IS,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFPOS2(:,IS-1,:) = 1./6.* (-1.0*PSRC(:,IS-2,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBPOS2(:,IS-1,:) = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IS-2,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IS-1
+ ZOMP2(:,IS-1:IS,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS-1:IS,:))**2  ! Non-normalized weight IS,IS-1
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFNEG3(:,IS-1,:) = 1./6 * (-1.0*PSRC(:,IS-2,:)   + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBNEG3(:,IS-1,:) = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS-1
+ ZOMN3(:,IS-1:IS,:) = 3./10. / (ZEPS + ZBNEG3(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+! 
+ ELSE ! North boundary is proc border, with NHALO < 3 on south side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on south side'
+  CALL ABORT
+ ENDIF
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IS,:)   = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! Flux IS
+ ZFPOS3(:,IS-1,:) = 1./6 * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) - PSRC(:,IS+1,:)) ! Flux IS-1
+ ZBPOS3(:,IS,:)   = 13./12 * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 ! Smoothness indicator IS
+ ZBPOS3(:,IS-1,:) = 13./12 * (    PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 ! Smoothness indicator IS-1
+ ZOMP3(:,IS-1:IS,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(:,IS,:)   = 1./6. * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) + 2.0*PSRC(:,IS+3,:)) ! Flux IS
+ ZFNEG1(:,IS-1,:) = 1./6. * (11.0*PSRC(:,IS,:)   - 7.0*PSRC(:,IS+1,:) + 2.0*PSRC(:,IS+2,:)) ! Flux IS-1
+ ZBNEG1(:,IS,:)   = 13./12. * (    PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2  ! Smoothness indicator IS
+ ZBNEG1(:,IS-1,:) = 13./12. * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2  ! Smoothness indicator IS-1
+ ZOMN1(:,IS-1:IS,:) = 1./10. / (ZEPS + ZBNEG1(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS,:)   + 5.0*PSRC(:,IS+1,:) - 1.0*PSRC(:,IS+2,:)) ! Flux IS
+ ZFNEG2(:,IS-1,:) = 1./6. * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   - 1.0*PSRC(:,IS+1,:)) ! Flux IS-1
+ ZBNEG2(:,IS,:)   = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (PSRC(:,IS,:) -                      PSRC(:,IS+2,:))**2 ! Smoothness indicator IS
+ ZBNEG2(:,IS-1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS-1
+ ZOMN2(:,IS-1:IS,:) = 3./5. / (ZEPS + ZBNEG2(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IS-1:IS,:) = ( ZOMP1(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS1(:,IS-1:IS,:) &
+                       + ZOMP2(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS2(:,IS-1:IS,:) & 
+                       + ZOMP3(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS3(:,IS-1:IS,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IS-1:IS,:))) &
+                    + ( ZOMN1(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG1(:,IS-1:IS,:) &
+                       + ZOMN2(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG2(:,IS-1:IS,:) &
+                       + ZOMN3(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG3(:,IS-1:IS,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IS-1:IS,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IS-1
+    PR(:,IS-1,:) = PSRC(:,IS-1,:) * (0.5+SIGN(0.5,PRVCT(:,IS-1,:))) + &
+                   PSRC(:,IS,:) * &
+                   (0.5-SIGN(0.5,PRVCT(:,IS-1,:)))
+!
+!   ! WENO scheme order 3, IS
+    ZFPOS1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS-1,:)) ! First positive flux
+    ZFPOS2(:,IS,:) = 0.5 * ( PSRC(:,IS,:) + PSRC(:,IS+1,:)) ! Second positive flux
+    ZBPOS1(:,IS,:) = (PSRC(:,IS,:)   - PSRC(:,IS-1,:))**2 ! First positive smoothness indicator
+    ZBPOS2(:,IS,:) = (PSRC(:,IS+1,:) - PSRC(:,IS,:))**2  ! Second positive smoothness indicator
+!
+    ZFNEG1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! First negative flux
+    ZFNEG2(:,IS,:) = 0.5 * ( PSRC(:,IS,:)   + PSRC(:,IS+1,:)) ! Second negative flux
+    ZBNEG1(:,IS,:) = (PSRC(:,IS+1,:) - PSRC(:,IS+2,:))**2 ! First negative smoothness indicator
+    ZBNEG2(:,IS,:) = (PSRC(:,IS,:)   - PSRC(:,IS+1,:))**2 ! Second negative smoothness indicator
+!
+    ZOMP1(:,IS,:) = 1./3. / (ZEPS + ZBPOS1(:,IS,:))**2 ! First positive non-normalized weight
+    ZOMP2(:,IS,:) = 2./3. / (ZEPS + ZBPOS2(:,IS,:))**2 ! Second positive non-normalized weight
+    ZOMN1(:,IS,:) = 1./3. / (ZEPS + ZBNEG1(:,IS,:))**2 ! First negative non-normalized weight
+    ZOMN2(:,IS,:) = 2./3. / (ZEPS + ZBNEG2(:,IS,:))**2 ! Second negative non-normalized weight
+! 
+    PR(:,IS,:) = (ZOMN2(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG2(:,IS,:) + &
+             (ZOMN1(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG1(:,IS,:))) &
+           *(0.5-SIGN(0.5,PRVCT(:,IS,:))) + &
+     (ZOMP2(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS2(:,IS,:) + &
+     (ZOMP1(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS1(:,IS,:))) &
+     *(0.5+SIGN(0.5,PRVCT(:,IS,:)))  ! Total flux
+! 
+ END SELECT ! SELECT CASE (HLBCY(1)) ! Y direction LBC type on south side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! South border is proc border -- IS,IS-1
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+!
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS-2,:) - 7.0*PSRC(:,IS-1,:) + 11.0*PSRC(:,IS,:)) ! Flux IS
+ ZFPOS1(:,IS-1,:) = 1./6. * (2.0*PSRC(:,IS-3,:) - 7.0*PSRC(:,IS-2,:) + 11.0*PSRC(:,IS-1,:)) ! Flux IS-1
+ ZBPOS1(:,IS,:)   = 13./12. * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 & 
+        + 1./4    * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2   ! Smoothness indicator IS
+ ZBPOS1(:,IS-1,:) = 13./12. * (PSRC(:,IS-3,:) - 2.0*PSRC(:,IS-2,:) +     PSRC(:,IS-1,:))**2 & 
+        + 1./4    * (PSRC(:,IS-3,:) - 4.0*PSRC(:,IS-2,:) + 3.0*PSRC(:,IS-1,:))**2  ! Smoothness indicator IS-1
+ ZOMP1(:,IS-1:IS,:)  = 1./10. / (ZEPS + ZBPOS1(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(:,IS,:)   = 1./6.* (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFPOS2(:,IS-1,:) = 1./6.* (-1.0*PSRC(:,IS-2,:) + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBPOS2(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBPOS2(:,IS-1,:) = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IS-2,:) -                      PSRC(:,IS,:))**2 ! Smoothness indicator IS-1
+ ZOMP2(:,IS-1:IS,:)  = 3./5. / (ZEPS + ZBPOS2(:,IS-1:IS,:))**2  ! Non-normalized weight IS,IS-1
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IS,:)   = 1./6 * (2.0*PSRC(:,IS,:) + 5.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:)) ! Flux IS
+ ZFPOS3(:,IS-1,:) = 1./6 * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:) - PSRC(:,IS+1,:)) ! Flux IS-1
+ ZBPOS3(:,IS,:)   = 13./12 * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 ! Smoothness indicator IS
+ ZBPOS3(:,IS-1,:) = 13./12 * (    PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 ! Smoothness indicator IS-1
+ ZOMP3(:,IS-1:IS,:)  = 3./10. / (ZEPS + ZBPOS3(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(:,IS,:)   = 1./6. * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) + 2.0*PSRC(:,IS+3,:)) ! Flux IS
+ ZFNEG1(:,IS-1,:) = 1./6. * (11.0*PSRC(:,IS,:)   - 7.0*PSRC(:,IS+1,:) + 2.0*PSRC(:,IS+2,:)) ! Flux IS-1
+ ZBNEG1(:,IS,:)   = 13./12. * (    PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2  ! Smoothness indicator IS
+ ZBNEG1(:,IS-1,:) = 13./12. * (    PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2  ! Smoothness indicator IS-1
+ ZOMN1(:,IS-1:IS,:) = 1./10. / (ZEPS + ZBNEG1(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(:,IS,:)   = 1./6. * (2.0*PSRC(:,IS,:)   + 5.0*PSRC(:,IS+1,:) - 1.0*PSRC(:,IS+2,:)) ! Flux IS
+ ZFNEG2(:,IS-1,:) = 1./6. * (2.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   - 1.0*PSRC(:,IS+1,:)) ! Flux IS-1
+ ZBNEG2(:,IS,:)   = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2 &
+      + 1./4   * (PSRC(:,IS,:) -                      PSRC(:,IS+2,:))**2 ! Smoothness indicator IS
+ ZBNEG2(:,IS-1,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 &
+      + 1./4   * (PSRC(:,IS-1,:) -                    PSRC(:,IS+1,:))**2 ! Smoothness indicator IS-1
+ ZOMN2(:,IS-1:IS,:) = 3./5. / (ZEPS + ZBNEG2(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(:,IS,:)   = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IS
+ ZFNEG3(:,IS-1,:) = 1./6 * (-1.0*PSRC(:,IS-2,:) + 5.0*PSRC(:,IS-1,:) + 2.0*PSRC(:,IS,:)) ! Flux IS-1
+ ZBNEG3(:,IS,:)   = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) +     PSRC(:,IS+1,:))**2 &
+        + 1./4   * (PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2 ! Smoothness indicator IS
+ ZBNEG3(:,IS-1,:) = 13./12 * (PSRC(:,IS-2,:) - 2.0*PSRC(:,IS-1,:) +     PSRC(:,IS,:))**2 &
+        + 1./4   * (PSRC(:,IS-2,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2 ! Smoothness indicator IS-1
+ ZOMN3(:,IS-1:IS,:) = 3./10. / (ZEPS + ZBNEG3(:,IS-1:IS,:))**2 ! Non-normalized weight IS,IS-1
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IS-1:IS,:) = ( ZOMP1(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS1(:,IS-1:IS,:) &
+                       + ZOMP2(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS2(:,IS-1:IS,:) & 
+                       + ZOMP3(:,IS-1:IS,:)/(ZOMP1(:,IS-1:IS,:)+ZOMP2(:,IS-1:IS,:)+ZOMP3(:,IS-1:IS,:)) * ZFPOS3(:,IS-1:IS,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IS-1:IS,:))) &
+                    + ( ZOMN1(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG1(:,IS-1:IS,:) &
+                       + ZOMN2(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG2(:,IS-1:IS,:) &
+                       + ZOMN3(:,IS-1:IS,:)/(ZOMN1(:,IS-1:IS,:)+ZOMN2(:,IS-1:IS,:)+ZOMN3(:,IS-1:IS,:)) * ZFNEG3(:,IS-1:IS,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IS-1:IS,:)))
 !
-  ZFNEG2(:,IS:IN-1,:) = 1./6 * (2.0*PSRC(:,IS:IN-1,:) + 5.0*PSRC(:,IS+1:IN,:) - &
-  1.0*PSRC(:,IS+2:IN+1,:))
-  ZFNEG2(:,IS-1,:) = 0.5 * (PSRC(:,IS-1,:) + PSRC(:,IS,  :))
-  ZFNEG2(:,IN,  :) = 0.5 * (PSRC(:,IN,  :) + PSRC(:,IN+1,:))
-  ZFNEG2(:,IN+1,:) = 0.5 * (PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))
+ END IF ! NHALO
 !
+END IF ! IF(LSOUTH_ll()) 
 !
-  ZFNEG3(:,IS:IN-1,:) = 1./6 * (-1.0*PSRC(:,IS-1:IN-2,:) + 5.0*PSRC(:,IS:IN-1,:) + &
-  2.0*PSRC(:,IS+1:IN,:))
+!-------------------------------------------------------------------------------
+!*       1.3.   North border
+!               ---------------------
 !
-! smoothness indicators for positive wind case
+IF(LNORTH_ll()  .AND. .FALSE. ) THEN 
+ !-----------------------------------------------------------------------------
+ ! North border is physical -- IN-1,IN
+ !-----------------------------------------------------------------------------
+ SELECT CASE (HLBCY(2)) ! Y direction LBC type on north side
+! 
+ CASE ('CYCL')
+ !---------------------------------------------------------------------------
+ ! Periodic boundary condition
+ !---------------------------------------------------------------------------
+! 
+ IF(LSOUTH_ll()  .AND. .FALSE. ) THEN  ! South border is physical 
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IS,:)) ! Flux IN
+ ZBPOS3(:,IN-1,:) = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2  ! Smoothness indicator IN
+ ZOMP3(:,IN-1:IN,:)  = 3./10. / (ZEPS + ZBPOS3(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(:,IN-1,:) = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IS,:)) ! Flux IN-1
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IS,:)   + 2.0*PSRC(:,IS+1,:)) ! Flux IN
+ ZBNEG1(:,IN-1,:) = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2  ! Smoothness indicator IN-1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IS,:) + PSRC(:,IS+1,:))**2  ! Smoothness indicator IN
+ ZOMN1(:,IN-1:IN,:) = 1./10. / (ZEPS + ZBNEG1(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(:,IN-1,:) = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IS,:)) ! Flux IN
+ ZBNEG2(:,IN-1,:)  = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IS,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IS,:))**2  ! Smoothness indicator IN
+ ZOMN2(:,IN-1:IN,:) = 3./5. / (ZEPS + ZBNEG2(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ELSEIF(IN<=SIZE(PSRC,2)-3) THEN ! South boundary is proc border, with minimum 3 HALO points on north side
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IN+2,:)) ! Flux IN
+ ZBPOS3(:,IN-1,:) = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 ! Smoothness indicator IN
+ ZOMP3(:,IN-1:IN,:)  = 3./10. / (ZEPS + ZBPOS3(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(:,IN-1,:) = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IN+2,:)) ! Flux IN-1
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IN+2,:)   + 2.0*PSRC(:,IN+3,:)) ! Flux IN
+ ZBNEG1(:,IN-1,:) = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN-1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2  ! Smoothness indicator IN
+ ZOMN1(:,IN-1:IN,:) = 1./10. / (ZEPS + ZBNEG1(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(:,IN-1,:) = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IN+2,:)) ! Flux IN
+ ZBNEG2(:,IN-1,:)  = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IN+2,:))**2 ! Smoothness indicator IN
+ ZOMN2(:,IN-1:IN,:) = 3./5. / (ZEPS + ZBNEG2(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ELSE ! South boundary is proc border, with NHALO < 3 on north side
+  PRINT *,'WARNING : WENO5 fluxes calculation needs NHALO >= 3 on north side'
+  CALL ABORT
+ ENDIF
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(:,IN-1,:) = 1./6. * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + 11.0*PSRC(:,IN-1,:)) ! Flux IN-1
+ ZFPOS1(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-2,:) - 7.0*PSRC(:,IN-1,:) + 11.0*PSRC(:,IN,:)) ! Flux IN
+ ZBPOS1(:,IN-1,:) = 13./12. * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) +     PSRC(:,IN-1,:))**2 & 
+        + 1./4    * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2  ! Smoothness indicator IN-1
+ ZBPOS1(:,IN,:)   = 13./12. * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 & 
+        + 1./4    * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2  ! Smoothness indicator IN
+ ZOMP1(:,IN-1:IN,:)  = 1./10. / (ZEPS + ZBPOS1(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(:,IN-1,:) = 1./6. * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN-1
+ ZFPOS2(:,IN,:)   = 1./6. * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZBPOS2(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + PSRC(:,IN,:))**2 &
+      + 1./4   * (PSRC(:,IN-2,:) -                      PSRC(:,IN,:))**2 ! Smoothness indicator IN-1
+ ZBPOS2(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                   PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZOMP2(:,IN-1:IN,:)  = 3./5. / (ZEPS + ZBPOS2(:,IN-1:IN,:))**2  ! Non-normalized weight IN-1,IN
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(:,IN-1,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN-1
+ ZFNEG3(:,IN,:)   = 1./6 * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZBNEG3(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 &
+        + 1./4   * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2 ! Smoothness indicator IN-1
+ ZBNEG3(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IN+1,:))**2 &
+        + 1./4   * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZOMN3(:,IN-1:IN,:) = 3./10. / (ZEPS + ZBNEG3(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IN-1:IN,:) = ( ZOMP1(:,IN-1:IN,:)/(ZOMP1(:,IN-1:IN,:)+ZOMP2(:,IN-1:IN,:)+ZOMP3(:,IN-1:IN,:)) * ZFPOS1(:,IN-1:IN,:) &
+                       + ZOMP2(:,IN-1:IN,:)/(ZOMP1(:,IN-1:IN,:)+ZOMP2(:,IN-1:IN,:)+ZOMP3(:,IN-1:IN,:)) * ZFPOS2(:,IN-1:IN,:) & 
+                       + ZOMP3(:,IN-1:IN,:)/(ZOMP1(:,IN-1:IN,:)+ZOMP2(:,IN-1:IN,:)+ZOMP3(:,IN-1:IN,:)) * ZFPOS3(:,IN-1:IN,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IN-1:IN,:))) &
+                    + ( ZOMN1(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG1(:,IN-1:IN,:) &
+                       + ZOMN2(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG2(:,IN-1:IN,:) &
+                       + ZOMN3(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG3(:,IN-1:IN,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IN-1:IN,:)))
+!
+!
+ CASE ('OPEN','WALL','NEST') 
+ !---------------------------------------------------------------------------
+ ! Open, or Wall, or Nest boundary condition => WENO order reduction
+ !---------------------------------------------------------------------------
+!
+ ! WENO scheme order 1, IN
+    PR(:,IN,:) = PSRC(:,IN,:) * (0.5+SIGN(0.5,PRVCT(:,IN,:))) + &
+                 PSRC(:,IN+1,:) * &
+                 (0.5-SIGN(0.5,PRVCT(:,IN,:)))
 !
-  ZBPOS1(:,IS+1:IN-1,:) = 13./12 * (PSRC(:,IS-1:IN-3,:) - 2.0*PSRC(:,IS:IN-2,:) +&
-  PSRC(:,IS+1:IN-1,:))**2 + &
-   1./4 * (PSRC(:,IS-1:IN-3,:) - 4.0*PSRC(:,IS:IN-2,:) + 3.0*PSRC(:,IS+1:IN-1,:))**2
-  ZBPOS1(:,IS,       :) = 13./12 * (TPHALO2%SOUTH(:,:) - 2.0*PSRC(:,IS-1,:) +&
-  PSRC(:,IS,:))**2 + &
-   1./4 * (TPHALO2%SOUTH(:,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2
-  ZBPOS1(:,IN+1,:) = (PSRC(:,IN+1,:) - PSRC(:,IN,  :))**2
-  ZBPOS1(:,IN,  :) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-  ZBPOS1(:,IS-1,:) = (PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))**2
-!
-!
-  ZBPOS2(:,IS:IN-1,:) = 13./12 * (PSRC(:,IS-1:IN-2,:) - 2.0*PSRC(:,IS:IN-1,:) + &
-  PSRC(:,IS+1:IN,:))**2 + &
-   1./4 * (PSRC(:,IS-1:IN-2,:) - PSRC(:,IS+1:IN,:))**2
-  ZBPOS2(:,IS-1,:) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-  ZBPOS2(:,IN,  :) = (PSRC(:,IN+1,:) - PSRC(:,IN,  :))**2
-  ZBPOS2(:,IN+1,:) = (TPHALO2%NORTH(:,:) - PSRC(:,IN+1,:))**2
-!
-  ZBPOS3(:,IS:IN-1,:) = 13./12 * (PSRC(:,IS:IN-1,:) - 2.0*PSRC(:,IS+1:IN,:) + &
-  PSRC(:,IS+2:IN+1,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS:IN-1,:) - 4.0*PSRC(:,IS+1:IN,:) + PSRC(:,IS+2:IN+1,:))**2
-!
-! smoothness indicators for negative wind case
-!
-  ZBNEG1(:,IS:IN-2,:) = 13./12 * (PSRC(:,IS+1:IN-1,:) - 2.0*PSRC(:,IS+2:IN,:) + &
-  PSRC(:,IS+3:IN+1,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS+1:IN-1,:) - 4.0*PSRC(:,IS+2:IN,:) + &
-   PSRC(:,IS+3:IN+1,:))**2
-  ZBNEG1(:,IN-1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + &
-  TPHALO2%NORTH(:,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))**2
-  ZBNEG1(:,IS-1,:) = (PSRC(:,IS,:) - PSRC(:,IS+1,:))**2
-  ZBNEG1(:,IN+1,:) = - 999.
-  ZBNEG1(:,IN,  :) = (PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))**2
-!
-  ZBNEG2(:,IS:IN-1,:) = 13./12 * (PSRC(:,IS:IN-1,:) - 2.0*PSRC(:,IS+1:IN,:) + &
-  PSRC(:,IS+2:IN+1,:))**2 + &
-   1./4 * (PSRC(:,IS:IN-1,:) - PSRC(:,IS+2:IN+1,:))**2
-  ZBNEG2(:,IS-1,:) = (PSRC(:,IS-1,:) - PSRC(:,IS  ,:))**2
-  ZBNEG2(:,IN,  :) = (PSRC(:,IN,  :) - PSRC(:,IN+1,:))**2
-  ZBNEG2(:,IN+1,:) = (PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))**2 
-!
-!
-  ZBNEG3(:,IS:IN-1,:) = 13./12 * (PSRC(:,IS-1:IN-2,:) - 2.0*PSRC(:,IS:IN-1,:) + &
-  PSRC(:,IS+1:IN,:))**2 + &
-   1./4 * ( PSRC(:,IS-1:IN-2,:) - 4.0*PSRC(:,IS:IN-1,:) + 3.0*PSRC(:,IS+1:IN,:))**2
+!   ! WENO scheme order 3, IN-1
+    ZFPOS1(:,IN-1,:) = 0.5 * (3.0*PSRC(:,IN-1,:) - PSRC(:,IN-2,:)) ! First positive flux
+    ZFPOS2(:,IN-1,:) = 0.5 * (    PSRC(:,IN-1,:) + PSRC(:,IN,:)) ! Second positive flux
+    ZBPOS1(:,IN-1,:) = (PSRC(:,IN-1,:) - PSRC(:,IN-2,:))**2 ! First positive smoothness indicator
+    ZBPOS2(:,IN-1,:) = (PSRC(:,IN,:)   - PSRC(:,IN-1,:))**2 ! Second positive smoothness indicator
+!
+    ZFNEG1(:,IN-1,:) = 0.5 * (3.0*PSRC(:,IN,:)   - PSRC(:,IN+1,:)) ! First negative flux
+    ZFNEG2(:,IN-1,:) = 0.5 * (    PSRC(:,IN-1,:) + PSRC(:,IN,:)) ! Second negative flux
+    ZBNEG1(:,IN-1,:) = (PSRC(:,IN,:)   - PSRC(:,IN+1,:))**2 ! First negative smoothness indicator
+    ZBNEG2(:,IN-1,:) = (PSRC(:,IN-1,:) - PSRC(:,IN,:))**2  ! Second negative smoothness indicator
+!
+    ZOMP1(:,IN-1,:) = 1./3. / (ZEPS + ZBPOS1(:,IN-1,:))**2 ! First positive non-normalized weight
+    ZOMP2(:,IN-1,:) = 2./3. / (ZEPS + ZBPOS2(:,IN-1,:))**2 ! Second positive non-normalized weight
+    ZOMN1(:,IN-1,:) = 1./3. / (ZEPS + ZBNEG1(:,IN-1,:))**2 ! First negative non-normalized weight
+    ZOMN2(:,IN-1,:) = 2./3. / (ZEPS + ZBNEG2(:,IN-1,:))**2 ! Second negative non-normalized weight
+! 
+    PR(:,IN-1,:) = (ZOMN2(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:))*ZFNEG2(:,IN-1,:) + &
+      (ZOMN1(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:))*ZFNEG1(:,IN-1,:))) &
+      *(0.5-SIGN(0.5,PRVCT(:,IN-1,:))) + &
+                 (ZOMP2(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:))*ZFPOS2(:,IN-1,:) + &
+                   (ZOMP1(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:))*ZFPOS1(:,IN-1,:))) &
+      * (0.5+SIGN(0.5,PRVCT(:,IN-1,:)))  ! Total flux
+! 
+ END SELECT ! SELECT CASE (HLBCY(2)) ! Y direction LBC type on north side
+!
+ELSE
+ !-----------------------------------------------------------------------------
+ ! North border is proc border -- IN-1,IN
+ !-----------------------------------------------------------------------------
+!
+ IF (NHALO<3) THEN
+ PRINT *,'WARNING : WENO5 not parallelisable with NHALO < 3' 
+ CALL ABORT
+ ELSEIF (NHALO>=3) THEN
+ !---------------------------------------------------------------------------
+ ! NHALO >= 3 => WENO5 for all boundary points
+ !---------------------------------------------------------------------------
+! 
+ ! ----- Positive fluxes -----
+!
+ ! First positive stencil, needs indices i-2, i-1, i 
+ ZFPOS1(:,IN-1,:) = 1./6. * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + 11.0*PSRC(:,IN-1,:)) ! Flux IN-1
+ ZFPOS1(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN-2,:) - 7.0*PSRC(:,IN-1,:) + 11.0*PSRC(:,IN,:)) ! Flux IN
+ ZBPOS1(:,IN-1,:) = 13./12. * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) +     PSRC(:,IN-1,:))**2 & 
+        + 1./4    * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2  ! Smoothness indicator IN-1
+ ZBPOS1(:,IN,:)   = 13./12. * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 & 
+        + 1./4    * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2  ! Smoothness indicator IN
+ ZOMP1(:,IN-1:IN,:)  = 1./10. / (ZEPS + ZBPOS1(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Second positive stencil, needs indices i-1, i, i+1
+ ZFPOS2(:,IN-1,:) = 1./6. * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN-1
+ ZFPOS2(:,IN,:)   = 1./6. * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZBPOS2(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + PSRC(:,IN,:))**2 &
+      + 1./4   * (PSRC(:,IN-2,:) -                      PSRC(:,IN,:))**2 ! Smoothness indicator IN-1
+ ZBPOS2(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                   PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZOMP2(:,IN-1:IN,:)  = 3./5. / (ZEPS + ZBPOS2(:,IN-1:IN,:))**2  ! Non-normalized weight IN-1,IN
+! 
+ ! Third positive stencil, needs indices i, i+1, i+2
+ ZFPOS3(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFPOS3(:,IN,:)   = 1./6 * (2.0*PSRC(:,IN,:) + 5.0*PSRC(:,IN+1,:) - PSRC(:,IN+2,:)) ! Flux IN
+ ZBPOS3(:,IN-1,:) = 13./12 * (    PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBPOS3(:,IN,:)   = 13./12 * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN
+ ZOMP3(:,IN-1:IN,:)  = 3./10. / (ZEPS + ZBPOS3(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! ----- Negative fluxes ----- 
+!
+ ! First negative stencil, needs indices i+1, i+2, i+3
+ ZFNEG1(:,IN-1,:) = 1./6. * (11.0*PSRC(:,IN,:)   - 7.0*PSRC(:,IN+1,:) + 2.0*PSRC(:,IN+2,:)) ! Flux IN-1
+ ZFNEG1(:,IN,:)   = 1./6. * (11.0*PSRC(:,IN+1,:) - 7.0*PSRC(:,IN+2,:) + 2.0*PSRC(:,IN+3,:)) ! Flux IN
+ ZBNEG1(:,IN-1,:) = 13./12. * (    PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2  ! Smoothness indicator IN-1
+ ZBNEG1(:,IN,:)   = 13./12. * (    PSRC(:,IN+1,:) - 2.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2 & 
+      + 1./4    * (3.0*PSRC(:,IN+1,:) - 4.0*PSRC(:,IN+2,:) + PSRC(:,IN+3,:))**2  ! Smoothness indicator IN
+ ZOMN1(:,IN-1:IN,:) = 1./10. / (ZEPS + ZBNEG1(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Second negative stencil, needs indices i, i+1, i+2
+ ZFNEG2(:,IN-1,:) = 1./6. * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   - 1.0*PSRC(:,IN+1,:)) ! Flux IN-1
+ ZFNEG2(:,IN,:)   = 1./6. * (2.0*PSRC(:,IN,:)   + 5.0*PSRC(:,IN+1,:) - 1.0*PSRC(:,IN+2,:)) ! Flux IN
+ ZBNEG2(:,IN-1,:)  = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2 &
+      + 1./4   * (PSRC(:,IN-1,:) -                    PSRC(:,IN+1,:))**2 ! Smoothness indicator IN-1
+ ZBNEG2(:,IN,:)   = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + PSRC(:,IN+2,:))**2 &
+      + 1./4   * (PSRC(:,IN,:) -                      PSRC(:,IN+2,:))**2 ! Smoothness indicator IN
+ ZOMN2(:,IN-1:IN,:) = 3./5. / (ZEPS + ZBNEG2(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! Third negative stencil, needs indices i-1, i, i+1
+ ZFNEG3(:,IN-1,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + 2.0*PSRC(:,IN,:)) ! Flux IN-1
+ ZFNEG3(:,IN,:)   = 1./6 * (-1.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:)   + 2.0*PSRC(:,IN+1,:)) ! Flux IN
+ ZBNEG3(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) +     PSRC(:,IN,:))**2 &
+        + 1./4   * (PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2 ! Smoothness indicator IN-1
+ ZBNEG3(:,IN,:)   = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) +     PSRC(:,IN+1,:))**2 &
+        + 1./4   * (PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + 3.0*PSRC(:,IN+1,:))**2 ! Smoothness indicator IN
+ ZOMN3(:,IN-1:IN,:) = 3./10. / (ZEPS + ZBNEG3(:,IN-1:IN,:))**2 ! Non-normalized weight IN-1,IN
+!
+ ! ----- Total flux -----
+! 
+ PR(:,IN-1:IN,:) = ( ZOMP1(:,IN-1:IN,:) /(ZOMP1(:,IN-1:IN,:) +ZOMP2(:,IN-1:IN,:) +ZOMP3(:,IN-1:IN,:)) * ZFPOS1(:,IN-1:IN,:) &
+                       + ZOMP2(:,IN-1:IN,:) /(ZOMP1(:,IN-1:IN,:) +ZOMP2(:,IN-1:IN,:) +ZOMP3(:,IN-1:IN,:)) * ZFPOS2(:,IN-1:IN,:) & 
+                       + ZOMP3(:,IN-1:IN,:) /(ZOMP1(:,IN-1:IN,:) +ZOMP2(:,IN-1:IN,:) +ZOMP3(:,IN-1:IN,:)) * ZFPOS3(:,IN-1:IN,:)) &
+                      * (0.5+SIGN(0.5,PRVCT(:,IN-1:IN,:))) &
+                    + ( ZOMN1(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG1(:,IN-1:IN,:) &
+                       + ZOMN2(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG2(:,IN-1:IN,:) &
+                       + ZOMN3(:,IN-1:IN,:)/(ZOMN1(:,IN-1:IN,:)+ZOMN2(:,IN-1:IN,:)+ZOMN3(:,IN-1:IN,:)) * ZFNEG3(:,IN-1:IN,:)) &
+                      * (0.5-SIGN(0.5,PRVCT(:,IN-1:IN,:)))
+! 
+ END IF ! NHALO
 !
-! WENO weights
+END IF ! IF(LNORTH_ll()) 
+!-------------------------------------------------------------------------------
 !
-  ZOMP1(:,IS:IN-1,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS:IN-1,:))**2
-  ZOMP2(:,IS:IN-1,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS:IN-1,:))**2
-  ZOMP3(:,IS:IN-1,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS:IN-1,:))**2
-  ZOMN1(:,IS:IN-1,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS:IN-1,:))**2
-  ZOMN2(:,IS:IN-1,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS:IN-1,:))**2
-  ZOMN3(:,IS:IN-1,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS:IN-1,:))**2
-!
-  ZOMP1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS-1,:))**2
-  ZOMP1(:,IN,  :) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN,  :))**2
-  ZOMP1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN+1,:))**2
-  ZOMN1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS-1,:))**2
-  ZOMN1(:,IN,  :) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN,  :))**2
-  ZOMN1(:,IN+1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN+1,:))**2
-  ZOMP2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS-1,:))**2
-  ZOMP2(:,IN,  :) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN,  :))**2
-  ZOMP2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN+1,:))**2
-  ZOMN2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS-1,:))**2
-  ZOMN2(:,IN,  :) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN,  :))**2
-  ZOMN2(:,IN+1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN+1,:))**2
-!
-! WENO fluxes (5th order)
-!
-  PR(:,IS:IN-1,:) = (ZOMP2(:,IS:IN-1,:)/(ZOMP1(:,IS:IN-1,:)+ZOMP2(:,IS:IN-1,:)+&
-  ZOMP3(:,IS:IN-1,:)) * ZFPOS2(:,IS:IN-1,:)                                    &
-                   + ZOMP1(:,IS:IN-1,:)/(ZOMP1(:,IS:IN-1,:)+ZOMP2(:,IS:IN-1,:)+&
-                   ZOMP3(:,IS:IN-1,:)) * ZFPOS1(:,IS:IN-1,:)                   &
-                   + ZOMP3(:,IS:IN-1,:)/(ZOMP1(:,IS:IN-1,:)+ZOMP2(:,IS:IN-1,:)+&
-                   ZOMP3(:,IS:IN-1,:)) * ZFPOS3(:,IS:IN-1,:))&
-                   * (0.5+SIGN(0.5,PRVCT(:,IS:IN-1,:))) &
-                  + (ZOMN2(:,IS:IN-1,:)/(ZOMN1(:,IS:IN-1,:)+ZOMN2(:,IS:IN-1,:)+&
-                  ZOMN3(:,IS:IN-1,:)) * ZFNEG2(:,IS:IN-1,:)                  &
-                   + ZOMN1(:,IS:IN-1,:)/(ZOMN1(:,IS:IN-1,:)+ZOMN2(:,IS:IN-1,:)+&
-                   ZOMN3(:,IS:IN-1,:)) * ZFNEG1(:,IS:IN-1,:)                   &
-                   + ZOMN3(:,IS:IN-1,:)/(ZOMN1(:,IS:IN-1,:)+ZOMN2(:,IS:IN-1,:)+&
-                   ZOMN3(:,IS:IN-1,:)) * ZFNEG3(:,IS:IN-1,:))&
-                   * (0.5-SIGN(0.5,PRVCT(:,IS:IN-1,:)))
-!       
-  PR(:,IS-1,:) = (ZOMP2(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS2(:,IS-1,:)                                    &
-                + ZOMP1(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS1(:,IS-1,:)) * (0.5+SIGN(0.5,PRVCT(:,IS-1,:))) &
-               + (ZOMN2(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                  ZFNEG2(:,IS-1,:)                                    &
-                + ZOMN1(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                ZFNEG1(:,IS-1,:)) * (0.5-SIGN(0.5,PRVCT(:,IS-1,:)))
-!
-  PR(:,IN,  :) = (ZOMP2(:,IN,  :)/(ZOMP1(:,IN,  :)+ZOMP2(:,IN,  :)) * &
-                  ZFPOS2(:,IN,  :)                                    &
-                + ZOMP1(:,IN,  :)/(ZOMP1(:,IN,  :)+ZOMP2(:,IN,  :)) * &
-                  ZFPOS1(:,IN,  :)) * (0.5+SIGN(0.5,PRVCT(:,IN,  :))) &
-               + (ZOMN2(:,IN,  :)/(ZOMN1(:,IN,  :)+ZOMN2(:,IN,  :)) * &
-                  ZFNEG2(:,IN,  :)                                    &
-                + ZOMN1(:,IN,  :)/(ZOMN1(:,IN,  :)+ZOMN2(:,IN,  :)) * &
-                ZFNEG1(:,IN,  :)) * (0.5-SIGN(0.5,PRVCT(:,IN,  :)))
-!
-  PR(:,IN+1,:) = (ZOMP2(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:)) * &
-                  ZFPOS2(:,IN+1,:)                                    &
-                + ZOMP1(:,IN+1,:)/(ZOMP1(:,IN+1,:)+ZOMP2(:,IN+1,:)) * &
-                  ZFPOS1(:,IN+1,:)) * (0.5+SIGN(0.5,PRVCT(:,IN+1,:))) &
-               + (ZOMN2(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                  ZFNEG2(:,IN+1,:)                                    &
-                + ZOMN1(:,IN+1,:)/(ZOMN1(:,IN+1,:)+ZOMN2(:,IN+1,:)) * &
-                  ZFNEG1(:,IN+1,:)) * (0.5-SIGN(0.5,PRVCT(:,IN+1,:)))
-!
-!
-!       OPEN, WALL, NEST CASE IN THE Y DIRECTION
-!
-CASE ('OPEN','WALL','NEST')
-!
-  IS=IJB
-  IN=IJE
-!
-!       USE A FIRST ORDER UPSTREAM SCHEME AT THE PHYSICAL BORDER
-!
-  IF(LSOUTH_ll()) THEN
-    PR(:,IS-1,:) = PSRC(:,IS-1,:) * (0.5+SIGN(0.5,PRVCT(:,IS-1,:))) + &
-                   PSRC(:,IS,:) * (0.5-SIGN(0.5,PRVCT(:,IS-1,:)))
-!
-    ZFPOS1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS-1,:))
-    ZFPOS2(:,IS,:) = 0.5 * (PSRC(:,IS,    :) + PSRC(:,IS+1,:))
-    ZBPOS1(:,IS,:) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-    ZBPOS2(:,IS,:) = (PSRC(:,IS+1,:) - PSRC(:,IS,  :))**2
-!
-    ZFNEG1(:,IS,:) = 0.5 * (3.0*PSRC(:,IS+1,:) - PSRC(:,IS+2,:))
-    ZFNEG2(:,IS,:) = 0.5 * (PSRC(:,IS,      :) + PSRC(:,IS+1,:))
-    ZBNEG1(:,IS,:) = (PSRC(:,IS+1,:) - PSRC(:,IS+2,:))**2
-    ZBNEG2(:,IS,:) = (PSRC(:,IS,  :) - PSRC(:,IS+1,:))**2
-!
-    ZOMP1(:,IS,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS,:))**2
-    ZOMP2(:,IS,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS,:))**2
-    ZOMN1(:,IS,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS,:))**2
-    ZOMN2(:,IS,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS,:))**2
-!
-      PR(:,IS,:) = (ZOMP2(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS2(:,IS,:) &
-                + ZOMP1(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)) * ZFPOS1(:,IS,:)) *&
-                (0.5+SIGN(0.5,PRVCT(:,IS,:))) &
-               + (ZOMN2(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG2(:,IS,:)   &
-                + ZOMN1(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)) * ZFNEG1(:,IS,:)) *&
-                (0.5-SIGN(0.5,PRVCT(:,IS,:)))
-!
-  ELSEIF(NHALO == 1) THEN
-    ZFPOS1(:,IS-1,:) = 0.5 * (3.0*PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))
-    ZFPOS2(:,IS-1,:) = 0.5 * (PSRC(:,IS-1,    :) + PSRC(:,IS,:))
-    ZBPOS1(:,IS-1,:) = (PSRC(:,IS-1,:) - TPHALO2%SOUTH(:,:))**2
-    ZBPOS2(:,IS-1,:) = (PSRC(:,IS,  :) - PSRC(:,IS-1,:))**2
-!
-    ZFNEG1(:,IS-1,:) = 0.5 * (3.0*PSRC(:,IS,:) - PSRC(:,IS+1,:))
-    ZFNEG2(:,IS-1,:) = 0.5 * (PSRC(:,IS-1,  :) + PSRC(:,IS,  :))
-    ZBNEG1(:,IS-1,:) = (PSRC(:,IS,  :) - PSRC(:,IS+1,:))**2
-    ZBNEG2(:,IS-1,:) = (PSRC(:,IS-1,:) - PSRC(:,IS,  :))**2
-!
-    ZOMP1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IS-1,:))**2
-    ZOMN1(:,IS-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IS-1,:))**2
-    ZOMP2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IS-1,:))**2
-    ZOMN2(:,IS-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IS-1,:))**2
-!
-    PR(:,IS-1,:) = (ZOMP2(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS2(:,IS-1,:)                                  &
-                + ZOMP1(:,IS-1,:)/(ZOMP1(:,IS-1,:)+ZOMP2(:,IS-1,:)) * &
-                  ZFPOS1(:,IS-1,:)) * (0.5+SIGN(0.5,PRVCT(:,IS-1,:))) &
-               + (ZOMN2(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                  ZFNEG2(:,IS-1,:)                                    &
-                + ZOMN1(:,IS-1,:)/(ZOMN1(:,IS-1,:)+ZOMN2(:,IS-1,:)) * &
-                  ZFNEG1(:,IS-1,:)) * (0.5-SIGN(0.5,PRVCT(:,IS-1,:)))
-!
-    ZFPOS1(:,IS,:) = 1./6 * (2.0*TPHALO2%SOUTH(:,:) - 7.0*PSRC(:,IS-1,:) + &
-                     11.0*PSRC(:,IS,:))
-    ZFPOS2(:,IS,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,  :) + &
-                     2.0*PSRC(:,IS+1,:))
-    ZFPOS3(:,IS,:) = 1./6 * (2.0*PSRC(:,IS,   :) + 5.0*PSRC(:,IS+1,:) - &
-                     1.0*PSRC(:,IS+2,:))
-!
-    ZFNEG1(:,IS,:) = 1./6 * (11.0*PSRC(:,IS+1,:) - 7.0*PSRC(:,IS+2,:) + &
-                     2.0*PSRC(:,IS+3,:))
-    ZFNEG2(:,IS,:) = 1./6 * (2.0*PSRC(:,IS,   :) + 5.0*PSRC(:,IS+1,:) - &
-                     1.0*PSRC(:,IS+2,:))
-    ZFNEG3(:,IS,:) = 1./6 * (-1.0*PSRC(:,IS-1,:) + 5.0*PSRC(:,IS,  :) + &
-                     2.0*PSRC(:,IS+1,:))
-!
-    ZBPOS1(:,IS,:) = 13./12 * (TPHALO2%SOUTH(:,:) - 2.0*PSRC(:,IS-1,:) + &
-                     PSRC(:,IS,:))**2 + &
-     1./4 * (TPHALO2%SOUTH(:,:) - 4.0*PSRC(:,IS-1,:) + 3.0*PSRC(:,IS,:))**2
-    ZBPOS2(:,IS,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + &
-                     PSRC(:,IS+1,:))**2 + &
-     1./4 * (PSRC(:,IS-1,:) - PSRC(:,IS+1,:))**2
-    ZBPOS3(:,IS,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + &
-     PSRC(:,IS+2,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IS,:) - 4.0*PSRC(:,IS+1,:) + PSRC(:,IS+2,:))**2
-!
-    ZBNEG1(:,IS,:) = 13./12 * (PSRC(:,IS+1,:) - 2.0*PSRC(:,IS+2,:) + &
-     PSRC(:,IS+3,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IS+1,:) - 4.0*PSRC(:,IS+2,:) + PSRC(:,IS+3,:))**2
-    ZBNEG2(:,IS,:) = 13./12 * (PSRC(:,IS,:) - 2.0*PSRC(:,IS+1,:) + &
-     PSRC(:,IS+2,:))**2 + &
-     1./4 * (PSRC(:,IS,:) - PSRC(:,IS+2,:))**2
-    ZBNEG3(:,IS,:) = 13./12 * (PSRC(:,IS-1,:) - 2.0*PSRC(:,IS,:) + &
-     PSRC(:,IS+1,:))**2 + &
-     1./4 * ( PSRC(:,IS-1,:) - 4.0*PSRC(:,IS,:) + 3.0*PSRC(:,IS+1,:))**2
-!
-    ZOMP1(:,IS,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS,:))**2
-    ZOMP2(:,IS,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS,:))**2
-    ZOMP3(:,IS,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS,:))**2
-    ZOMN1(:,IS,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS,:))**2
-    ZOMN2(:,IS,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS,:))**2
-    ZOMN3(:,IS,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS,:))**2
-!
-    PR(:,IS,:) = (ZOMP2(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)+ZOMP3(:,IS,:)) * &
-     ZFPOS2(:,IS,:)                                  &
-     + ZOMP1(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)+ZOMP3(:,IS,:)) * ZFPOS1(:,IS,:)&
-     + ZOMP3(:,IS,:)/(ZOMP1(:,IS,:)+ZOMP2(:,IS,:)+ZOMP3(:,IS,:)) * ZFPOS3(:,IS,:))&
-     * (0.5+SIGN(0.5,PRVCT(:,IS,:))) &
-     + (ZOMN2(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)+ZOMN3(:,IS,:)) * ZFNEG2(:,IS,:)&
-     + ZOMN1(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)+ZOMN3(:,IS,:)) * ZFNEG1(:,IS,:)&
-     + ZOMN3(:,IS,:)/(ZOMN1(:,IS,:)+ZOMN2(:,IS,:)+ZOMN3(:,IS,:)) * ZFNEG3(:,IS,:))&
-     * (0.5-SIGN(0.5,PRVCT(:,IS,:)))
-!       
-  ENDIF
-!
-  IF(LNORTH_ll()) THEN
-    PR(:,IN,:) = PSRC(:,IN,:) * (0.5+SIGN(0.5,PRVCT(:,IN,:))) + PSRC(:,IN+1,:) *&
-     (0.5-SIGN(0.5,PRVCT(:,IN,:)))
-!
-    ZFPOS1(:,IN-1,:) = 0.5 * (3.0*PSRC(:,IN-1,:) - PSRC(:,IN-2,:))
-    ZFPOS2(:,IN-1,:) = 0.5 * (PSRC(:,IN-1,    :) + PSRC(:,IN,  :))
-    ZBPOS1(:,IN-1,:) = (PSRC(:,IN-1,:) - PSRC(:,IN-2,:))**2
-    ZBPOS2(:,IN-1,:) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-!
-    ZFNEG1(:,IN-1,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN+1,:))
-    ZFNEG2(:,IN-1,:) = 0.5 * (PSRC(:,IN-1,  :) + PSRC(:,IN,  :))
-    ZBNEG1(:,IN-1,:) = (PSRC(:,IN,:) - PSRC(:,IN+1,:))**2
-    ZBNEG2(:,IN-1,:) = (PSRC(:,IN-1,:) - PSRC(:,IN,:))**2
-!
-    ZOMP1(:,IN-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN-1,:))**2
-    ZOMN1(:,IN-1,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN-1,:))**2
-    ZOMP2(:,IN-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN-1,:))**2
-    ZOMN2(:,IN-1,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN-1,:))**2
-!
-      PR(:,IN-1,:) = (ZOMP2(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:)) * &
-                ZFPOS2(:,IN-1,:)                                   &
-                + ZOMP1(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:)) * &
-                ZFPOS1(:,IN-1,:)) * (0.5+SIGN(0.5,PRVCT(:,IN-1,:)))    &
-               + (ZOMN2(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:)) *  &
-                ZFNEG2(:,IN-1,:)                                       &
-                + ZOMN1(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:)) *  &
-                ZFNEG1(:,IN-1,:)) * (0.5-SIGN(0.5,PRVCT(:,IN-1,:)))
-!
-  ELSEIF(NHALO == 1) THEN
-    ZFPOS1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN,:) - PSRC(:,IN-1,:))
-    ZFPOS2(:,IN,:) = 0.5 * (PSRC(:,IN,    :) + PSRC(:,IN+1,:))
-    ZBPOS1(:,IN,:) = (PSRC(:,IN,  :) - PSRC(:,IN-1,:))**2
-    ZBPOS2(:,IN,:) = (PSRC(:,IN+1,:) - PSRC(:,IN,  :))**2
-!
-    ZFNEG1(:,IN,:) = 0.5 * (3.0*PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))
-    ZFNEG2(:,IN,:) = 0.5 * (PSRC(:,IN,      :) + PSRC(:,IN+1,:))
-    ZBNEG1(:,IN,:) = (PSRC(:,IN+1,:) - TPHALO2%NORTH(:,:))**2
-    ZBNEG2(:,IN,:) = (PSRC(:,IN,  :) - PSRC(:,IN+1,:))**2
- !
-    ZOMP1(:,IN,:) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,IN,:))**2
-    ZOMN1(:,IN,:) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,IN,:))**2
-    ZOMP2(:,IN,:) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,IN,:))**2
-    ZOMN2(:,IN,:) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,IN,:))**2
-!
-      PR(:,IN,:) = (ZOMP2(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)) * ZFPOS2(:,IN,:) &
-                + ZOMP1(:,IN,:)/(ZOMP1(:,IN,:)+ZOMP2(:,IN,:)) * ZFPOS1(:,IN,:)) *&
-                (0.5+SIGN(0.5,PRVCT(:,IN,:))) &
-               + (ZOMN2(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)) * ZFNEG2(:,IN,:)   &
-                + ZOMN1(:,IN,:)/(ZOMN1(:,IN,:)+ZOMN2(:,IN,:)) * ZFNEG1(:,IN,:)) *&
-                (0.5-SIGN(0.5,PRVCT(:,IN,:)))
-!
-    ZFPOS1(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-3,:) - 7.0*PSRC(:,IN-2,:) + &
-                       11.0*PSRC(:,IN-1,:))
-    ZFPOS2(:,IN-1,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + &
-                       2.0*PSRC(:,IN,:))
-    ZFPOS3(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-1,:) + 5.0*PSRC(:,IN,:) - &
-                       1.0*PSRC(:,IN+1,:))
-!
-    ZFNEG1(:,IN-1,:) = 1./6 * (11.0*PSRC(:,IN,  :) - 7.0*PSRC(:,IN+1,:) + &
-                       2.0*TPHALO2%NORTH(:,:))
-    ZFNEG2(:,IN-1,:) = 1./6 * (2.0*PSRC(:,IN-1, :) + 5.0*PSRC(:,IN,  :) - &
-                       1.0*PSRC(:,IN+1,:))
-    ZFNEG3(:,IN-1,:) = 1./6 * (-1.0*PSRC(:,IN-2,:) + 5.0*PSRC(:,IN-1,:) + &
-                       2.0*PSRC(:,IN,  :))
-!
-    ZBPOS1(:,IN-1,:) = 13./12 * (PSRC(:,IN-3,:) - 2.0*PSRC(:,IN-2,:) + &
-                       PSRC(:,IN-1,:))**2 + &
-     1./4 * (PSRC(:,IN-3,:) - 4.0*PSRC(:,IN-2,:) + 3.0*PSRC(:,IN-1,:))**2
-    ZBPOS2(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + &
-                       PSRC(:,IN,:))**2 + &
-     1./4 * (PSRC(:,IN-2,:) - PSRC(:,IN,:))**2
-    ZBPOS3(:,IN-1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + &
-    PSRC(:,IN+1,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IN-1,:) - 4.0*PSRC(:,IN,:) + PSRC(:,IN+1,:))**2
-!
-    ZBNEG1(:,IN-1,:) = 13./12 * (PSRC(:,IN,:) - 2.0*PSRC(:,IN+1,:) + &
-     TPHALO2%NORTH(:,:))**2 + &
-     1./4 * ( 3.0*PSRC(:,IN,:) - 4.0*PSRC(:,IN+1,:) + TPHALO2%NORTH(:,:))**2
-    ZBNEG2(:,IN-1,:) = 13./12 * (PSRC(:,IN-1,:) - 2.0*PSRC(:,IN,:) + &
-     PSRC(:,IN+1,:))**2 + &
-     1./4 * (PSRC(:,IN-1,:) - PSRC(:,IN+1,:))**2
-    ZBNEG3(:,IN-1,:) = 13./12 * (PSRC(:,IN-2,:) - 2.0*PSRC(:,IN-1,:) + &
-     PSRC(:,IN,:))**2 + &
-     1./4 * ( PSRC(:,IN-2,:) - 4.0*PSRC(:,IN-1,:) + 3.0*PSRC(:,IN,:))**2
-!
-    ZOMP1(:,IN-1,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IN-1,:))**2
-    ZOMP2(:,IN-1,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IN-1,:))**2
-    ZOMP3(:,IN-1,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IN-1,:))**2
-    ZOMN1(:,IN-1,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IN-1,:))**2
-    ZOMN2(:,IN-1,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IN-1,:))**2
-    ZOMN3(:,IN-1,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IN-1,:))**2
-!
-    PR(:,IN-1,:) = (ZOMP2(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:)+ &
-      ZOMP3(:,IN-1,:)) * ZFPOS2(:,IN-1,:)                             &
-                   + ZOMP1(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:)+&
-                   ZOMP3(:,IN-1,:)) * ZFPOS1(:,IN-1,:)                &
-                   + ZOMP3(:,IN-1,:)/(ZOMP1(:,IN-1,:)+ZOMP2(:,IN-1,:)+&
-                   ZOMP3(:,IN-1,:)) * ZFPOS3(:,IN-1,:))               &
-                   * (0.5+SIGN(0.5,PRVCT(:,IN-1,:)))                  &
-                  + (ZOMN2(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:)+&
-                  ZOMN3(:,IN-1,:)) * ZFNEG2(:,IN-1,:)                 &
-                   + ZOMN1(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:)+&
-                   ZOMN3(:,IN-1,:)) * ZFNEG1(:,IN-1,:)                &
-                   + ZOMN3(:,IN-1,:)/(ZOMN1(:,IN-1,:)+ZOMN2(:,IN-1,:)+&
-                   ZOMN3(:,IN-1,:)) * ZFNEG3(:,IN-1,:))               &
-                   * (0.5-SIGN(0.5,PRVCT(:,IN-1,:)))
-!       
-  ENDIF
-!
-  ZFPOS1(:,IS+1:IN-2,:) = 1./6 * (2.0*PSRC(:,IS-1:IN-4,:) - 7.0*PSRC(:,IS:IN-3,:) +&
-   11.0*PSRC(:,IS+1:IN-2,:))
-  ZFPOS2(:,IS+1:IN-2,:) = 1./6 * (-1.0*PSRC(:,IS:IN-3,:) + 5.0*PSRC(:,IS+1:IN-2,:)+&
-   2.0*PSRC(:,IS+2:IN-1,:))
-  ZFPOS3(:,IS+1:IN-2,:) = 1./6 * (2.0*PSRC(:,IS+1:IN-2,:) + 5.0*PSRC(:,IS+2:IN-1,:)&
-  - 1.0*PSRC(:,IS+3:IN,:))
-!
-  ZBPOS1(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS-1:IN-4,:) - 2.0*PSRC(:,IS:IN-3,:) + &
-   PSRC(:,IS+1:IN-2,:))**2 + &
-   1./4 * (PSRC(:,IS-1:IN-4,:) - 4.0*PSRC(:,IS:IN-3,:) + 3.0*PSRC(:,IS+1:IN-2,:))**2
-  ZBPOS2(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS:IN-3,:) - 2.0*PSRC(:,IS+1:IN-2,:) + &
-   PSRC(:,IS+2:IN-1,:))**2 + &
-   1./4 * (PSRC(:,IS:IN-3,:) - PSRC(:,IS+2:IN-1,:))**2
-  ZBPOS3(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS+1:IN-2,:) - 2.0*PSRC(:,IS+2:IN-1,:) +&
-   PSRC(:,IS+3:IN,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS+1:IN-2,:) - 4.0*PSRC(:,IS+2:IN-1,:) + &
-   PSRC(:,IS+3:IN,:))**2
-!
-  ZFNEG1(:,IS+1:IN-2,:) = 1./6 * (11.0*PSRC(:,IS+2:IN-1,:) - &
-   7.0*PSRC(:,IS+3:IN,:) + 2.0*PSRC(:,IS+4:IN+1,:))
-  ZFNEG2(:,IS+1:IN-2,:) = 1./6 * (2.0*PSRC(:,IS+1:IN-2,:) + &
-   5.0*PSRC(:,IS+2:IN-1,:) - 1.0*PSRC(:,IS+3:IN,:))
-  ZFNEG3(:,IS+1:IN-2,:) = 1./6 * (-1.0*PSRC(:,IS:IN-3,:) + &
-   5.0*PSRC(:,IS+1:IN-2,:) + 2.0*PSRC(:,IS+2:IN-1,:))
-!
-  ZBNEG1(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS+2:IN-1,:) - &
-   2.0*PSRC(:,IS+3:IN,:) + PSRC(:,IS+4:IN+1,:))**2 + &
-   1./4 * ( 3.0*PSRC(:,IS+2:IN-1,:) - 4.0*PSRC(:,IS+3:IN,:) + &
-   PSRC(:,IS+4:IN+1,:))**2
-  ZBNEG2(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS+1:IN-2,:) - &
-   2.0*PSRC(:,IS+2:IN-1,:) + PSRC(:,IS+3:IN,:))**2 + &
-   1./4 * (PSRC(:,IS+1:IN-2,:) - PSRC(:,IS+3:IN,:))**2
-  ZBNEG3(:,IS+1:IN-2,:) = 13./12 * (PSRC(:,IS:IN-3,:) - &
-   2.0*PSRC(:,IS+1:IN-2,:) + PSRC(:,IS+2:IN-1,:))**2 + &
-   1./4 * ( PSRC(:,IS:IN-3,:) - 4.0*PSRC(:,IS+1:IN-2,:) + &
-   3.0*PSRC(:,IS+2:IN-1,:))**2
-!
-  ZOMP1(:,IS+1:IN-2,:) = ZGAMMA1 / (ZEPS + ZBPOS1(:,IS+1:IN-2,:))**2
-  ZOMP2(:,IS+1:IN-2,:) = ZGAMMA2 / (ZEPS + ZBPOS2(:,IS+1:IN-2,:))**2
-  ZOMP3(:,IS+1:IN-2,:) = ZGAMMA3 / (ZEPS + ZBPOS3(:,IS+1:IN-2,:))**2
-  ZOMN1(:,IS+1:IN-2,:) = ZGAMMA1 / (ZEPS + ZBNEG1(:,IS+1:IN-2,:))**2
-  ZOMN2(:,IS+1:IN-2,:) = ZGAMMA2 / (ZEPS + ZBNEG2(:,IS+1:IN-2,:))**2
-  ZOMN3(:,IS+1:IN-2,:) = ZGAMMA3 / (ZEPS + ZBNEG3(:,IS+1:IN-2,:))**2
-!
-  PR(:,IS+1:IN-2,:) = (ZOMP2(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+     &
-   ZOMP2(:,IS+1:IN-2,:)+ZOMP3(:,IS+1:IN-2,:)) * ZFPOS2(:,IS+1:IN-2,:)  &
-   + ZOMP1(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+                       &
-   ZOMP2(:,IS+1:IN-2,:)+ZOMP3(:,IS+1:IN-2,:)) * ZFPOS1(:,IS+1:IN-2,:)  &
-   + ZOMP3(:,IS+1:IN-2,:)/(ZOMP1(:,IS+1:IN-2,:)+ZOMP2(:,IS+1:IN-2,:)+  &
-   ZOMP3(:,IS+1:IN-2,:)) * ZFPOS3(:,IS+1:IN-2,:))                      &
-   * (0.5+SIGN(0.5,PRVCT(:,IS+1:IN-2,:)))                              &
-   + (ZOMN2(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+ &
-   ZOMN3(:,IS+1:IN-2,:)) * ZFNEG2(:,IS+1:IN-2,:)                       &
-   + ZOMN1(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+  &
-   ZOMN3(:,IS+1:IN-2,:)) * ZFNEG1(:,IS+1:IN-2,:)                       &
-   + ZOMN3(:,IS+1:IN-2,:)/(ZOMN1(:,IS+1:IN-2,:)+ZOMN2(:,IS+1:IN-2,:)+  &
-   ZOMN3(:,IS+1:IN-2,:)) * ZFNEG3(:,IS+1:IN-2,:))                      &
-   * (0.5-SIGN(0.5,PRVCT(:,IS+1:IN-2,:)))
-!
-END SELECT
-!
-PR = PR * PRVCT
+PR = PR * PRVCT ! Add contravariant flux
 !
 END SUBROUTINE ADVEC_WENO_K_3_VY
 !
@@ -2536,6 +2743,7 @@ END SUBROUTINE ADVEC_WENO_K_3_VY
 !!
 !!    MODIFICATIONS
 !!    -------------
+!! T. Lunet 02/10/2014:  Complete code documentation
 !!
 !-------------------------------------------------------------------------------
 !
@@ -2567,7 +2775,6 @@ INTEGER :: IT    ! End useful area in x,y,z directions
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -2581,14 +2788,8 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMN1, ZOMN2, ZOMN3
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
+! EPSILON for weno weights calculation
+! 
 REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !-------------------------------------------------------------------------------
@@ -2619,151 +2820,145 @@ ZOMP3  = 0.0
 ZOMN1  = 0.0
 ZOMN2  = 0.0
 ZOMN3  = 0.0 
-! 
-! r: many left cells in regard to 'k' cell for each stencil
-!
-! intermediate fluxes at the mass point on Wgrid u(i,j,k+1/2) for positive wind
-! case (left to the right)
-! (r=2 for the first stencil ZFPOS1, r=1 for the second ZFPOS2 and 
-!  r=0 for the last ZFPOS3)
-! 
-ZFPOS1(:,:,IB+1:IT-2) = 1./6 * (2.0*PSRC(:,:,IB-1:IT-4) - 7.0*PSRC(:,:,IB:IT-3) + &
- 11.0*PSRC(:,:,IB+1:IT-2))
-ZFPOS1(:,:,IB) = 0.5 * (3.0*PSRC(:,:,IB) - PSRC(:,:,IB-1))
-ZFPOS1(:,:,IT-1) = 0.5 * (3.0*PSRC(:,:,IT-1) - PSRC(:,:,IT-2))
-!
-!
-ZFPOS2(:,:,IB+1:IT-2) = 1./6 * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) +&
- 2.0*PSRC(:,:,IB+2:IT-1))
-ZFPOS2(:,:,IB) = 0.5 * (PSRC(:,:,IB) + PSRC(:,:,IB+1))
-ZFPOS2(:,:,IT-1) = 0.5 * (PSRC(:,:,IT) + PSRC(:,:,IT+1))
-!
-ZFPOS3(:,:,IB+1:IT-2) = 1./6 * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) -&
- 1.0*PSRC(:,:,IB+3:IT))
-!
-! r: many left cells in regard to 'k+1' cell for each stencil
-! 
-! intermediate flux at the mass point on Wgrid (i,j,k+1/2)=(i,j,(k+1)-1/2) 
-! for negative wind case (right to the left)
-! (r=2 for the last stencil ZFNEG3=ZFPOS2, r=1 for the second ZFNEG2=ZFPOS3 
-!  and r=0 for the first ZFNEG1)  
-!
-ZFNEG1(:,:,IB+1:IT-2) = 1./6 * (11.0*PSRC(:,:,IB+2:IT-1) - 7.0*PSRC(:,:,IB+3:IT) +&
- 2.0*PSRC(:,:,IB+4:IT+1))
-ZFNEG1(:,:,IT-1) = 0.5 * (3.0*PSRC(:,:,IT) - PSRC(:,:,IT+1))
-ZFNEG1(:,:,IB) = 0.5 * (3.0*PSRC(:,:,IB+1) - PSRC(:,:,IB+2))
-!
-!
-ZFNEG2(:,:,IB+1:IT-2) = 1./6 * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) -&
- 1.0*PSRC(:,:,IB+3:IT))
-ZFNEG2(:,:,IB) = 0.5 * (PSRC(:,:,IB) + PSRC(:,:,IB+1))
-ZFNEG2(:,:,IT-1) = 0.5 * (PSRC(:,:,IT-1) + PSRC(:,:,IT))
-!
-!
-ZFNEG3(:,:,IB+1:IT-2) = 1./6 * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + &
- 2.0*PSRC(:,:,IB+2:IT-1))
-!
-! smoothness indicators for positive wind case
-!
-ZBPOS1(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB-1:IT-4) - 2.0*PSRC(:,:,IB:IT-3) + &
- PSRC(:,:,IB+1:IT-2))**2 + &
- 1./4 * (PSRC(:,:,IB-1:IT-4) - 4.0*PSRC(:,:,IB:IT-3) + 3.0*PSRC(:,:,IB+1:IT-2))**2
-ZBPOS1(:,:,IB) = (PSRC(:,:,IB) - PSRC(:,:,IB-1))**2
-ZBPOS1(:,:,IT-1) = (PSRC(:,:,IT-1) - PSRC(:,:,IT-2))**2
-!
-!
-ZBPOS2(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) + &
- PSRC(:,:,IB+2:IT-1))**2 + &
- 1./4 * (PSRC(:,:,IB:IT-3) - PSRC(:,:,IB+2:IT-1))**2
-ZBPOS2(:,:,IB) = (PSRC(:,:,IB+1) - PSRC(:,:,IB))**2
-ZBPOS2(:,:,IT-1) = (PSRC(:,:,IT) - PSRC(:,:,IT-1))**2
-!
-!
-ZBPOS3(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + &
- PSRC(:,:,IB+3:IT))**2 + &
- 1./4 * ( 3.0*PSRC(:,:,IB+1:IT-2) - 4.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2
-!
-! smoothness indicators for negative wind case
-!
-ZBNEG1(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB+2:IT-1) - 2.0*PSRC(:,:,IB+3:IT) + &
- PSRC(:,:,IB+4:IT+1))**2 + &
- 1./4 * ( 3.0*PSRC(:,:,IB+2:IT-1) - 4.0*PSRC(:,:,IB+3:IT) + PSRC(:,:,IB+4:IT+1))**2
-ZBNEG1(:,:,IB) = (PSRC(:,:,IB+1) - PSRC(:,:,IB+2))**2
-ZBNEG1(:,:,IT-1) = (PSRC(:,:,IT) - PSRC(:,:,IT+1))**2
-!
-ZBNEG2(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + &
- PSRC(:,:,IB+3:IT))**2 + &
- 1./4 * (PSRC(:,:,IB+1:IT-2) - PSRC(:,:,IB+3:IT))**2
-ZBNEG2(:,:,IB) = (PSRC(:,:,IB) - PSRC(:,:,IB+1))**2
-ZBNEG2(:,:,IT-1) = (PSRC(:,:,IT-1) - PSRC(:,:,IT))**2
 !
+!-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
 !
-ZBNEG3(:,:,IB+1:IT-2) = 13./12 * (PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) + &
- PSRC(:,:,IB+2:IT-1))**2 + &
- 1./4 * ( PSRC(:,:,IB:IT-3) - 4.0*PSRC(:,:,IB+1:IT-2) + 3.0*PSRC(:,:,IB+2:IT-1))**2
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IB+1 -> IT-2
+! Computation at the mass point on Wgrid v(i+1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-! WENO weights
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-2, i-1, i
+ZFPOS1(:,:,IB+1:IT-2) = 1./6.   * (2.0*PSRC(:,:,IB-1:IT-4) - 7.0*PSRC(:,:,IB:IT-3) + 11.0*PSRC(:,:,IB+1:IT-2))   ! Flux
+ZBPOS1(:,:,IB+1:IT-2) = 13./12. * (    PSRC(:,:,IB-1:IT-4) - 2.0*PSRC(:,:,IB:IT-3) +      PSRC(:,:,IB+1:IT-2))**2 & 
+      + 1./4    * (    PSRC(:,:,IB-1:IT-4) - 4.0*PSRC(:,:,IB:IT-3) + 3.0* PSRC(:,:,IB+1:IT-2))**2  ! Smoothness indicator
+ZOMP1(:,:,IB+1:IT-2)  = 1./10. /  (ZEPS + ZBPOS1(:,:,IB+1:IT-2))**2             ! Non-normalized weight
+!
+! Second positive stencil, needs indices i-1, i, i+1
+ZFPOS2(:,:,IB+1:IT-2) = 1./6.  * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + 2.0*PSRC(:,:,IB+2:IT-1))  ! Flux
+ZBPOS2(:,:,IB+1:IT-2) = 13./12 * (     PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) +     PSRC(:,:,IB+2:IT-1))**2 &
+      + 1./4   * (     PSRC(:,:,IB:IT-3) -                               PSRC(:,:,IB+2:IT-1))**2 ! Smoothness indicator
+ZOMP2(:,:,IB+1:IT-2)  = 3./5. /  (ZEPS + ZBPOS2(:,:,IB+1:IT-2))**2             ! Non-normalized weight
+!
+! Third positive stencil, needs indices i, i+1, i+2
+ZFPOS3(:,:,IB+1:IT-2) = 1./6   * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) - PSRC(:,:,IB+3:IT))  ! Flux
+ZBPOS3(:,:,IB+1:IT-2) = 13./12 * ( PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2 &
+      + 1./4   * (3.0*PSRC(:,:,IB+1:IT-2) - 4.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2 ! Smoothness indicator
+ZOMP3(:,:,IB+1:IT-2)  = 3./10. / (ZEPS + ZBPOS3(:,:,IB+1:IT-2))**2           ! Non-normalized weight
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i+1, i+2, i+3
+ZFNEG1(:,:,IB+1:IT-2) = 1./6.   * (11.0*PSRC(:,:,IB+2:IT-1) - 7.0*PSRC(:,:,IB+3:IT) + 2.0*PSRC(:,:,IB+4:IT+1))   ! Flux
+ZBNEG1(:,:,IB+1:IT-2) = 13./12. * (     PSRC(:,:,IB+2:IT-1) - 2.0*PSRC(:,:,IB+3:IT) +     PSRC(:,:,IB+4:IT+1))**2 & 
+      + 1./4    * (3.0* PSRC(:,:,IB+2:IT-1) - 4.0*PSRC(:,:,IB+3:IT) +     PSRC(:,:,IB+4:IT+1))**2  ! Smoothness indicator
+ZOMN1(:,:,IB+1:IT-2)  = 1./10. /  (ZEPS + ZBNEG1(:,:,IB+1:IT-2))**2             ! Non-normalized weight
+!
+! Second negative stencil, needs indices i, i+1, i+2
+ZFNEG2(:,:,IB+1:IT-2) = 1./6.  * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) - 1.0*PSRC(:,:,IB+3:IT))  ! Flux
+ZBNEG2(:,:,IB+1:IT-2) = 13./12 * (    PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) +     PSRC(:,:,IB+3:IT))**2 &
+      + 1./4   * (    PSRC(:,:,IB+1:IT-2) -                               PSRC(:,:,IB+3:IT))**2 ! Smoothness indicator
+ZOMN2(:,:,IB+1:IT-2)  = 3./5. /  (ZEPS + ZBNEG2(:,:,IB+1:IT-2))**2            ! Non-normalized weight
+!
+! Third negative stencil, needs indices i-1, i, i+1
+ZFNEG3(:,:,IB+1:IT-2) = 1./6   * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + 2.0*PSRC(:,:,IB+2:IT-1))  ! Flux
+ZBNEG3(:,:,IB+1:IT-2) = 13./12 * (  PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) +     PSRC(:,:,IB+2:IT-1))**2 &
+      + 1./4   * (     PSRC(:,:,IB:IT-3) - 4.0*PSRC(:,:,IB+1:IT-2) + 3.0*PSRC(:,:,IB+2:IT-1))**2 ! Smoothness indicator
+ZOMN3(:,:,IB+1:IT-2)  = 3./10. / (ZEPS + ZBNEG3(:,:,IB+1:IT-2))**2             ! Non-normalized weight
+!
+!
+! ----- Total flux -----
+!
+PR(:,:,IB+1:IT-2) = (ZOMP1(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+ZOMP2(:,:,IB+1:IT-2)+ZOMP3(:,:,IB+1:IT-2)) &
+           * ZFPOS1(:,:,IB+1:IT-2) + &
+                      ZOMP2(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+ZOMP2(:,:,IB+1:IT-2)+ZOMP3(:,:,IB+1:IT-2)) &
+           * ZFPOS2(:,:,IB+1:IT-2) + & 
+                      ZOMP3(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+ZOMP2(:,:,IB+1:IT-2)+ZOMP3(:,:,IB+1:IT-2)) &
+           * ZFPOS3(:,:,IB+1:IT-2)) &
+                    * (0.5+SIGN(0.5,PRWCT(:,:,IB+1:IT-2))) &
+                  + (ZOMN1(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+ZOMN3(:,:,IB+1:IT-2)) &
+           * ZFNEG1(:,:,IB+1:IT-2)  &
+                     + ZOMN2(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+ZOMN3(:,:,IB+1:IT-2)) &
+           * ZFNEG2(:,:,IB+1:IT-2)  &
+                     + ZOMN3(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+ZOMN3(:,:,IB+1:IT-2)) &
+           * ZFNEG3(:,:,IB+1:IT-2))  & 
+                    * (0.5-SIGN(0.5,PRWCT(:,:,IB+1:IT-2)))
 !
-ZOMP1(:,:,IB+1:IT-2) = ZGAMMA1 / (ZEPS + ZBPOS1(:,:,IB+1:IT-2))**2
-ZOMP2(:,:,IB+1:IT-2) = ZGAMMA2 / (ZEPS + ZBPOS2(:,:,IB+1:IT-2))**2
-ZOMP3(:,:,IB+1:IT-2) = ZGAMMA3 / (ZEPS + ZBPOS3(:,:,IB+1:IT-2))**2
-ZOMN1(:,:,IB+1:IT-2) = ZGAMMA1 / (ZEPS + ZBNEG1(:,:,IB+1:IT-2))**2
-ZOMN2(:,:,IB+1:IT-2) = ZGAMMA2 / (ZEPS + ZBNEG2(:,:,IB+1:IT-2))**2
-ZOMN3(:,:,IB+1:IT-2) = ZGAMMA3 / (ZEPS + ZBNEG3(:,:,IB+1:IT-2))**2
-!
-ZOMP1(:,:,  IB) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,:,  IB))**2
-ZOMP2(:,:,  IB) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,:,  IB))**2
-ZOMN1(:,:,  IB) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,:,  IB))**2
-ZOMN2(:,:,  IB) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,:,  IB))**2
-ZOMP1(:,:,IT-1) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,:,IT-1))**2
-ZOMP2(:,:,IT-1) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,:,IT-1))**2
-ZOMN1(:,:,IT-1) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,:,IT-1))**2
-ZOMN2(:,:,IT-1) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,:,IT-1))**2
-!
-! WENO fluxes (5th order)
-!
-PR(:,:,IB+1:IT-2) = (ZOMP2(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+&
- ZOMP2(:,:,IB+1:IT-2)+ZOMP3(:,:,IB+1:IT-2)) * ZFPOS2(:,:,IB+1:IT-2) &
- + ZOMP1(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+ZOMP2(:,:,IB+1:IT-2)+ &
- ZOMP3(:,:,IB+1:IT-2)) * ZFPOS1(:,:,IB+1:IT-2)                      &
- + ZOMP3(:,:,IB+1:IT-2)/(ZOMP1(:,:,IB+1:IT-2)+ZOMP2(:,:,IB+1:IT-2)+ &
- ZOMP3(:,:,IB+1:IT-2)) * ZFPOS3(:,:,IB+1:IT-2))                     &
- * (0.5+SIGN(0.5,PRWCT(:,:,IB+1:IT-2)))                             &
- + (ZOMN2(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+&
- ZOMN3(:,:,IB+1:IT-2)) * ZFNEG2(:,:,IB+1:IT-2)                      &
- + ZOMN1(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+ &
- ZOMN3(:,:,IB+1:IT-2)) * ZFNEG1(:,:,IB+1:IT-2)                      &
- + ZOMN3(:,:,IB+1:IT-2)/(ZOMN1(:,:,IB+1:IT-2)+ZOMN2(:,:,IB+1:IT-2)+ &
- ZOMN3(:,:,IB+1:IT-2)) * ZFNEG3(:,:,IB+1:IT-2))                     &
- * (0.5-SIGN(0.5,PRWCT(:,:,IB+1:IT-2)))
-!
-! WENO fluxes (3rd order)
-!
-PR(:,:,IB) = (ZOMP2(:,:,IB)/(ZOMP1(:,:,IB)+ZOMP2(:,:,IB)) * ZFPOS2(:,:,IB)     &
-            + ZOMP1(:,:,IB)/(ZOMP1(:,:,IB)+ZOMP2(:,:,IB)) * ZFPOS1(:,:,IB)) *  &
-            (0.5+SIGN(0.5,PRWCT(:,:,IB) ))                                     &
-           + (ZOMN2(:,:,IB)/(ZOMN1(:,:,IB)+ZOMN2(:,:,IB)) * ZFNEG2(:,:,IB)     &
-            + ZOMN1(:,:,IB)/(ZOMN1(:,:,IB)+ZOMN2(:,:,IB)) * ZFNEG1(:,:,IB)) *  &
-            (0.5-SIGN(0.5,PRWCT(:,:,IB) ))
-!
-PR(:,:,IT-1) = (ZOMP2(:,:,IT-1)/(ZOMP1(:,:,IT-1)+ZOMP2(:,:,IT-1)) * &
-                ZFPOS2(:,:,IT-1)                                    &
-              + ZOMP1(:,:,IT-1)/(ZOMP1(:,:,IT-1)+ZOMP2(:,:,IT-1)) * &
-                ZFPOS1(:,:,IT-1)) * (0.5+SIGN(0.5,PRWCT(:,:,IT-1) ))&
-             + (ZOMN2(:,:,IT-1)/(ZOMN1(:,:,IT-1)+ZOMN2(:,:,IT-1)) * &
-                ZFNEG2(:,:,IT-1)                                    &
-              + ZOMN1(:,:,IT-1)/(ZOMN1(:,:,IT-1)+ZOMN2(:,:,IT-1)) * &
-                ZFNEG1(:,:,IT-1)) * (0.5-SIGN(0.5,PRWCT(:,:,IT-1) ))
+!-------------------------------------------------------------------------------
+!*       1.2.   Bottom border
+!               ---------------------
+!---------------------------------------------------------------------------
+! WENO order reduction
+!---------------------------------------------------------------------------
 !
+! WENO scheme order 1, IB-1
 PR(:,:,IB-1) =  PSRC(:,:,IB-1) * (0.5+SIGN(0.5,PRWCT(:,:,IB-1) )) &
               + PSRC(:,:,IB  ) * (0.5-SIGN(0.5,PRWCT(:,:,IB-1) ))
 !
+!   ! WENO scheme order 3, IB
+ZFPOS1(:,:,IB) = 0.5 * (3.0*PSRC(:,:,IB) - PSRC(:,:,IB-1)) ! First positive flux
+ZFPOS2(:,:,IB) = 0.5 * ( PSRC(:,:,IB) + PSRC(:,:,IB+1)) ! Second positive flux
+ZBPOS1(:,:,IB) = (PSRC(:,:,IB)   - PSRC(:,:,IB-1))**2 ! First positive smoothness indicator
+ZBPOS2(:,:,IB) = (PSRC(:,:,IB+1) - PSRC(:,:,IB))**2  ! Second positive smoothness indicator
+!
+ZFNEG1(:,:,IB) = 0.5 * (3.0*PSRC(:,:,IB+1) - PSRC(:,:,IB+2)) ! First negative flux
+ZFNEG2(:,:,IB) = 0.5 * ( PSRC(:,:,IB)   + PSRC(:,:,IB+1)) ! Second negative flux
+ZBNEG1(:,:,IB) = (PSRC(:,:,IB+1) - PSRC(:,:,IB+2))**2 ! First negative smoothness indicator
+ZBNEG2(:,:,IB) = (PSRC(:,:,IB)   - PSRC(:,:,IB+1))**2 ! Second negative smoothness indicator
+!
+ZOMP1(:,:,IB) = 1./3. / (ZEPS + ZBPOS1(:,:,IB))**2 ! First positive non-normalized weight
+ZOMP2(:,:,IB) = 2./3. / (ZEPS + ZBPOS2(:,:,IB))**2 ! Second positive non-normalized weight
+ZOMN1(:,:,IB) = 1./3. / (ZEPS + ZBNEG1(:,:,IB))**2 ! First negative non-normalized weight
+ZOMN2(:,:,IB) = 2./3. / (ZEPS + ZBNEG2(:,:,IB))**2 ! Second negative non-normalized weight
+! 
+PR(:,:,IB) = (ZOMN2(:,:,IB)/(ZOMN1(:,:,IB)+ZOMN2(:,:,IB)) * ZFNEG2(:,:,IB) + &
+         (ZOMN1(:,:,IB)/(ZOMN1(:,:,IB)+ZOMN2(:,:,IB)) * ZFNEG1(:,:,IB))) &
+       *(0.5-SIGN(0.5,PRWCT(:,:,IB))) + &
+    (ZOMP2(:,:,IB)/(ZOMP1(:,:,IB)+ZOMP2(:,:,IB)) * ZFPOS2(:,:,IB) + &
+    (ZOMP1(:,:,IB)/(ZOMP1(:,:,IB)+ZOMP2(:,:,IB)) * ZFPOS1(:,:,IB))) &
+    *(0.5+SIGN(0.5,PRWCT(:,:,IB)))  ! Total flux
+! 
+!-------------------------------------------------------------------------------
+!*       1.3.   Top border
+!               ---------------------
+!
+!---------------------------------------------------------------------------
+! Open, or Wall, or Nest boundary condition => WENO order reduction
+!---------------------------------------------------------------------------
+!
+! WENO scheme order 1, IT
 PR(:,:,IT) = PSRC(:,:,IT  ) * (0.5+SIGN(0.5,PRWCT(:,:,IT) )) &
            + PSRC(:,:,IT+1) * (0.5-SIGN(0.5,PRWCT(:,:,IT) ))
 !
-PR(:,:,IT+1) = -999.
+!   ! WENO scheme order 3, IT-1
+ZFPOS1(:,:,IT-1) = 0.5 * (3.0*PSRC(:,:,IT-1) - PSRC(:,:,IT-2)) ! First positive flux
+ZFPOS2(:,:,IT-1) = 0.5 * ( PSRC(:,:,IT-1) + PSRC(:,:,IT)) ! Second positive flux
+ZBPOS1(:,:,IT-1) = (PSRC(:,:,IT-1) - PSRC(:,:,IT-2))**2 ! First positive smoothness indicator
+ZBPOS2(:,:,IT-1) = (PSRC(:,:,IT)   - PSRC(:,:,IT-1))**2 ! Second positive smoothness indicator
+!
+ZFNEG1(:,:,IT-1) = 0.5 * (3.0*PSRC(:,:,IT)   - PSRC(:,:,IT+1)) ! First negative flux
+ZFNEG2(:,:,IT-1) = 0.5 * ( PSRC(:,:,IT-1) + PSRC(:,:,IT)) ! Second negative flux
+ZBNEG1(:,:,IT-1) = (PSRC(:,:,IT)   - PSRC(:,:,IT+1))**2 ! First negative smoothness indicator
+ZBNEG2(:,:,IT-1) = (PSRC(:,:,IT-1) - PSRC(:,:,IT))**2  ! Second negative smoothness indicator
+!
+ZOMP1(:,:,IT-1) = 1./3. / (ZEPS + ZBPOS1(:,:,IT-1))**2 ! First positive non-normalized weight
+ZOMP2(:,:,IT-1) = 2./3. / (ZEPS + ZBPOS2(:,:,IT-1))**2 ! Second positive non-normalized weight
+ZOMN1(:,:,IT-1) = 1./3. / (ZEPS + ZBNEG1(:,:,IT-1))**2 ! First negative non-normalized weight
+ZOMN2(:,:,IT-1) = 2./3. / (ZEPS + ZBNEG2(:,:,IT-1))**2 ! Second negative non-normalized weight
+! 
+PR(:,:,IT-1) = (ZOMN2(:,:,IT-1)/(ZOMN1(:,:,IT-1)+ZOMN2(:,:,IT-1))*ZFNEG2(:,:,IT-1) + &
+     (ZOMN1(:,:,IT-1)/(ZOMN1(:,:,IT-1)+ZOMN2(:,:,IT-1))*ZFNEG1(:,:,IT-1))) &
+     *(0.5-SIGN(0.5,PRWCT(:,:,IT-1))) + &
+             (ZOMP2(:,:,IT-1)/(ZOMP1(:,:,IT-1)+ZOMP2(:,:,IT-1))*ZFPOS2(:,:,IT-1) + &
+               (ZOMP1(:,:,IT-1)/(ZOMP1(:,:,IT-1)+ZOMP2(:,:,IT-1))*ZFPOS1(:,:,IT-1))) &
+     * (0.5+SIGN(0.5,PRWCT(:,:,IT-1)))  ! Total flux
 !
-PR = PR * PRWCT
+PR = PR * PRWCT ! Add contravariant flux
 !
 END FUNCTION WENO_K_3_WZ
 !
@@ -2784,6 +2979,7 @@ END FUNCTION WENO_K_3_WZ
 !!
 !!    MODIFICATIONS
 !!    -------------
+!! T. Lunet 02/10/2014:  Complete code documentation
 !!
 !-------------------------------------------------------------------------------
 !
@@ -2815,7 +3011,6 @@ INTEGER :: IT    ! End useful area in x,y,z directions
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFPOS1, ZFPOS2, ZFPOS3
 !
 ! intermediate reconstruction fluxes for negative wind case
-! we need only one since ZFNEG2 = ZFPOS2
 !
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZFNEG1, ZFNEG2, ZFNEG3
 !
@@ -2829,14 +3024,8 @@ REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZBNEG1, ZBNEG2, ZBNEG3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMP1, ZOMP2, ZOMP3
 REAL, DIMENSION(SIZE(PSRC,1),SIZE(PSRC,2),SIZE(PSRC,3)):: ZOMN1, ZOMN2, ZOMN3
 !
-! standard weights
-!
-REAL, PARAMETER :: ZGAMMA1 = 1./10.
-REAL, PARAMETER :: ZGAMMA2 = 3./5.
-REAL, PARAMETER :: ZGAMMA3 = 3./10.
-REAL, PARAMETER :: ZGAMMA1_PRIM = 1./3.
-REAL, PARAMETER :: ZGAMMA2_PRIM = 2./3.
-!
+! EPSILON for weno weights calculation
+! 
 REAL, PARAMETER :: ZEPS = 1.0E-15
 !
 !-------------------------------------------------------------------------------
@@ -2853,166 +3042,158 @@ ZFPOS1 = 0.0
 ZFPOS2 = 0.0
 ZFPOS3 = 0.0
 ZFNEG1 = 0.0
-ZFNEG2 = 0.0 
+ZFNEG2 = 0.0
 ZFNEG3 = 0.0
 ZBPOS1 = 0.0
 ZBPOS2 = 0.0
 ZBPOS3 = 0.0
 ZBNEG1 = 0.0
 ZBNEG2 = 0.0
-ZBNEG3 = 0.0 
+ZBNEG3 = 0.0
 ZOMP1  = 0.0
 ZOMP2  = 0.0
 ZOMP3  = 0.0
 ZOMN1  = 0.0
 ZOMN2  = 0.0
-ZOMN3  = 0.0
-!
-! r: many left cells in regard to 'k-1' cell for each stencil
-! 
-! intermediate fluxes at the mass point on Wgrid u(i,j,k-1/2)=(i,j,(k-1)-1/2) 
-! for positive wind case (left to the right)
-! (r=2 for the first stencil ZFPOS1, r=1 for the second ZFPOS2 and 
-! r=0 for the last ZFPOS3)
-!
-ZFPOS1(:,:,IB+2:IT-1) = 1./6 * (2.0*PSRC(:,:,IB-1:IT-4) - 7.0*PSRC(:,:,IB:IT-3) + &
- 11.0*PSRC(:,:,IB+1:IT-2))
-ZFPOS1(:,:,IB+1) = 0.5 * (3.0*PSRC(:,:,  IB) - PSRC(:,:,IB-1))
-ZFPOS1(:,:,  IT) = 0.5 * (3.0*PSRC(:,:,IT-1) - PSRC(:,:,IT-2))
-!
-!
-ZFPOS2(:,:,IB+2:IT-1) = 1./6 * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + &
- 2.0*PSRC(:,:,IB+2:IT-1))
-ZFPOS2(:,:,IB+1) = 0.5 * (PSRC(:,:,  IB) + PSRC(:,:,IB+1))
-ZFPOS2(:,:,  IT) = 0.5 * (PSRC(:,:,IT-1) + PSRC(:,:,  IT))
-!
-!
-ZFPOS3(:,:,IB+2:IT-1) = 1./6 * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) -&
- 1.0*PSRC(:,:,IB+3:IT)) 
-!
-! r: many left cells in regard to 'k' cell for each stencil
-!
-! intermediate fluxes at the mass point on Ugrid u(i,j,k-1/2) for negative wind
-! case (R. to the L.)
-! (r=2 for the third stencil ZFNEG3=ZFPOS2, r=1 for the second ZFNEG2=ZFPOS3 
-!  and r=0 for the first ZFNEG1)
-!
-ZFNEG1(:,:,IB+2:IT-1) = 1./6 * (11.0*PSRC(:,:,IB+2:IT-1) - 7.0*PSRC(:,:,IB+3:IT) + &
- 2.0*PSRC(:,:,IB+4:IT+1))
-ZFNEG1(:,:,IB+1) = 0.5 * (3.0*PSRC(:,:,IB+1) - PSRC(:,:,IB+2))
-ZFNEG1(:,:,  IT) = 0.5 * (3.0*PSRC(:,:,  IT) - PSRC(:,:,IT+1))
-!
-ZFNEG2(:,:,IB+2:IT-1) = 1./6 * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) -&
- 1.0*PSRC(:,:,IB+3:IT))
-ZFNEG2(:,:,IB+1) = 0.5 * (PSRC(:,:,  IB) + PSRC(:,:,IB+1))
-ZFNEG2(:,:,  IT) = 0.5 * (PSRC(:,:,IT-1) + PSRC(:,:,  IT))
-!
-!
-ZFNEG3(:,:,IB+2:IT-1) = 1./6 * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + &
- 2.0*PSRC(:,:,IB+2:IT-1))
-!
-! smoothness indicators for positive wind case
-!
-ZBPOS1(:,:,IB+2:IT-1) =  13./12 * (PSRC(:,:,IB-1:IT-4) - 2.0*PSRC(:,:,IB:IT-3) + &
- PSRC(:,:,IB+1:IT-2))**2 + &
- 1./4 * (PSRC(:,:,IB-1:IT-4) - 4.0*PSRC(:,:,IB:IT-3) + 3.0*PSRC(:,:,IB+1:IT-2))**2
-ZBPOS1(:,:,IB+1) = (PSRC(:,:,  IB) - PSRC(:,:,IB-1))**2
-ZBPOS1(:,:,  IT) = (PSRC(:,:,IT-1) - PSRC(:,:,IT-2))**2
-!
-!
-ZBPOS2(:,:,IB+2:IT-1) = 13./12 * (PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) + &
- PSRC(:,:,IB+2:IT-1))**2 + &
- 1./4 * (PSRC(:,:,IB:IT-3) - PSRC(:,:,IB+2:IT-1))**2
-ZBPOS2(:,:,IB+1) = (PSRC(:,:,IB+1) - PSRC(:,:,  IB))**2
-ZBPOS2(:,:,  IT) = (PSRC(:,:,  IT) - PSRC(:,:,IT-1))**2
-!
+ZOMN3  = 0.0 
 !
-ZBPOS3(:,:,IB+2:IT-1) = 13./12 * (PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + &
- PSRC(:,:,IB+3:IT))**2 + &
- 1./4 * ( 3.0*PSRC(:,:,IB+1:IT-2) - 4.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2
+!-------------------------------------------------------------------------------
+!*       1.1.   Interior Fluxes 
+!              ---------------------
 !
-! smoothness indicators for negative wind case
+!-------------------------------------------------------------------------------
+! Flux calculation in the physical domain far enough from the boundary 
+! WENO scheme order 5, IB+2 -> IT-1
+! Computation at the mass point on Wgrid v(i-1/2,j,k)
+!-------------------------------------------------------------------------------
 !
-ZBNEG1(:,:,IB+2:IT-1) = 13./12 * (PSRC(:,:,IB+2:IT-1) - 2.0*PSRC(:,:,IB+3:IT) + &
- PSRC(:,:,IB+4:IT+1))**2 + &
- 1./4 * ( 3.0*PSRC(:,:,IB+2:IT-1) - 4.0*PSRC(:,:,IB+3:IT) + PSRC(:,:,IB+4:IT+1))**2
-ZBNEG1(:,:,IB+1) = (PSRC(:,:,IB+1) - PSRC(:,:,IB+2))**2
-ZBNEG1(:,:,  IT) = (PSRC(:,:,  IT) - PSRC(:,:,IT+1))**2
+! ----- Positive fluxes -----
+!
+! First positive stencil, needs indices i-3, i-2, i-1
+ZFPOS1(:,:,IB+2:IT-1) = 1./6.   * (2.0*PSRC(:,:,IB-1:IT-4) - 7.0*PSRC(:,:,IB:IT-3) + 11.0*PSRC(:,:,IB+1:IT-2))   ! Flux
+ZBPOS1(:,:,IB+2:IT-1) = 13./12. * (    PSRC(:,:,IB-1:IT-4) - 2.0*PSRC(:,:,IB:IT-3) +      PSRC(:,:,IB+1:IT-2))**2 & 
+      + 1./4    * (    PSRC(:,:,IB-1:IT-4) - 4.0*PSRC(:,:,IB:IT-3) + 3.0* PSRC(:,:,IB+1:IT-2))**2  ! Smoothness indicator
+ZOMP1(:,:,IB+2:IT-1)  = 1./10. /  (ZEPS + ZBPOS1(:,:,IB+2:IT-1))**2             ! Non-normalized weight
+!
+! Second positive stencil, needs indices i-2, i-1, i
+ZFPOS2(:,:,IB+2:IT-1) = 1./6.  * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + 2.0*PSRC(:,:,IB+2:IT-1))  ! Flux
+ZBPOS2(:,:,IB+2:IT-1) = 13./12 * (     PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) +     PSRC(:,:,IB+2:IT-1))**2 &
+      + 1./4   * (     PSRC(:,:,IB:IT-3) -                               PSRC(:,:,IB+2:IT-1))**2 ! Smoothness indicator
+ZOMP2(:,:,IB+2:IT-1)  = 3./5. /  (ZEPS + ZBPOS2(:,:,IB+2:IT-1))**2             ! Non-normalized weight
+!
+! Third positive stencil, needs indices i-1, i, i+1
+ZFPOS3(:,:,IB+2:IT-1) = 1./6   * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) - PSRC(:,:,IB+3:IT))  ! Flux
+ZBPOS3(:,:,IB+2:IT-1) = 13./12 * ( PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2 &
+      + 1./4   * (3.0*PSRC(:,:,IB+1:IT-2) - 4.0*PSRC(:,:,IB+2:IT-1) + PSRC(:,:,IB+3:IT))**2 ! Smoothness indicator
+ZOMP3(:,:,IB+2:IT-1)  = 3./10. / (ZEPS + ZBPOS3(:,:,IB+2:IT-1))**2           ! Non-normalized weight
+!
+! ----- Negative fluxes ----- 
+!
+! First negative stencil, needs indices i, i+1, i+2
+ZFNEG1(:,:,IB+2:IT-1) = 1./6.   * (11.0*PSRC(:,:,IB+2:IT-1) - 7.0*PSRC(:,:,IB+3:IT) + 2.0*PSRC(:,:,IB+4:IT+1))   ! Flux
+ZBNEG1(:,:,IB+2:IT-1) = 13./12. * (     PSRC(:,:,IB+2:IT-1) - 2.0*PSRC(:,:,IB+3:IT) +     PSRC(:,:,IB+4:IT+1))**2 & 
+      + 1./4    * (3.0* PSRC(:,:,IB+2:IT-1) - 4.0*PSRC(:,:,IB+3:IT) +     PSRC(:,:,IB+4:IT+1))**2  ! Smoothness indicator
+ZOMN1(:,:,IB+2:IT-1)  = 1./10. /  (ZEPS + ZBNEG1(:,:,IB+2:IT-1))**2             ! Non-normalized weight
+!
+! Second negative stencil, needs indices i-1, i, i+1
+ZFNEG2(:,:,IB+2:IT-1) = 1./6.  * (2.0*PSRC(:,:,IB+1:IT-2) + 5.0*PSRC(:,:,IB+2:IT-1) - 1.0*PSRC(:,:,IB+3:IT))  ! Flux
+ZBNEG2(:,:,IB+2:IT-1) = 13./12 * (    PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) +     PSRC(:,:,IB+3:IT))**2 &
+      + 1./4   * (    PSRC(:,:,IB+1:IT-2) -                               PSRC(:,:,IB+3:IT))**2 ! Smoothness indicator
+ZOMN2(:,:,IB+2:IT-1)  = 3./5. /  (ZEPS + ZBNEG2(:,:,IB+2:IT-1))**2            ! Non-normalized weight
+!
+! Third negative stencil, needs indices i-2, i-1, i
+ZFNEG3(:,:,IB+2:IT-1) = 1./6   * (-1.0*PSRC(:,:,IB:IT-3) + 5.0*PSRC(:,:,IB+1:IT-2) + 2.0*PSRC(:,:,IB+2:IT-1))  ! Flux
+ZBNEG3(:,:,IB+2:IT-1) = 13./12 * (  PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) +     PSRC(:,:,IB+2:IT-1))**2 &
+      + 1./4   * (     PSRC(:,:,IB:IT-3) - 4.0*PSRC(:,:,IB+1:IT-2) + 3.0*PSRC(:,:,IB+2:IT-1))**2 ! Smoothness indicator
+ZOMN3(:,:,IB+2:IT-1)  = 3./10. / (ZEPS + ZBNEG3(:,:,IB+2:IT-1))**2             ! Non-normalized weight
+!
+!
+! ----- Total flux -----
+!
+PR(:,:,IB+2:IT-1) = (ZOMP1(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) &
+           * ZFPOS1(:,:,IB+2:IT-1) + &
+                      ZOMP2(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) &
+           * ZFPOS2(:,:,IB+2:IT-1) + & 
+                      ZOMP3(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) &
+           * ZFPOS3(:,:,IB+2:IT-1)) &
+                    * (0.5+SIGN(0.5,PRWCT(:,:,IB+2:IT-1))) &
+                  + (ZOMN1(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) &
+           * ZFNEG1(:,:,IB+2:IT-1)  &
+                     + ZOMN2(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) &
+           * ZFNEG2(:,:,IB+2:IT-1)  &
+                     + ZOMN3(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) &
+           * ZFNEG3(:,:,IB+2:IT-1))  & 
+                    * (0.5-SIGN(0.5,PRWCT(:,:,IB+2:IT-1)))
 !
-ZBNEG2(:,:,IB+2:IT-1) = 13./12 * (PSRC(:,:,IB+1:IT-2) - 2.0*PSRC(:,:,IB+2:IT-1) + &
- PSRC(:,:,IB+3:IT))**2 + &
- 1./4 * (PSRC(:,:,IB+1:IT-2) - PSRC(:,:,IB+3:IT))**2
-ZBNEG2(:,:,IB+1) = (PSRC(:,:,  IB) - PSRC(:,:,IB+1))**2
-ZBNEG2(:,:,  IT) = (PSRC(:,:,IT-1) - PSRC(:,:,  IT))**2
+!-------------------------------------------------------------------------------
+!*       1.2.   Bottom border
+!               ---------------------
+!---------------------------------------------------------------------------
+! WENO order reduction
+!---------------------------------------------------------------------------
 !
+! WENO scheme order 1, IB
+PR(:,:,IB) = PSRC(:,:,IB-1) * (0.5+SIGN(0.5,PRWCT(:,:,IB) )) &
+           + PSRC(:,:,IB  ) * (0.5-SIGN(0.5,PRWCT(:,:,IB) ))
 !
-ZBNEG3(:,:,IB+2:IT-1) = 13./12 * (PSRC(:,:,IB:IT-3) - 2.0*PSRC(:,:,IB+1:IT-2) + &
- PSRC(:,:,IB+2:IT-1))**2 + &
- 1./4 * ( PSRC(:,:,IB:IT-3) - 4.0*PSRC(:,:,IB+1:IT-2) + 3.0*PSRC(:,:,IB+2:IT-1))**2
+! WENO scheme order 3, IB+1
+ZFPOS1(:,:,IB+1) = 0.5 * (3.0*PSRC(:,:,IB) - PSRC(:,:,IB-1)) ! First positive flux
+ZFPOS2(:,:,IB+1) = 0.5 * ( PSRC(:,:,IB) + PSRC(:,:,IB+1)) ! Second positive flux
+ZBPOS1(:,:,IB+1) = (PSRC(:,:,IB)   - PSRC(:,:,IB-1))**2 ! First positive smoothness indicator
+ZBPOS2(:,:,IB+1) = (PSRC(:,:,IB+1) - PSRC(:,:,IB))**2  ! Second positive smoothness indicator
+!
+ZFNEG1(:,:,IB+1) = 0.5 * (3.0*PSRC(:,:,IB+1) - PSRC(:,:,IB+2)) ! First negative flux
+ZFNEG2(:,:,IB+1) = 0.5 * ( PSRC(:,:,IB)   + PSRC(:,:,IB+1)) ! Second negative flux
+ZBNEG1(:,:,IB+1) = (PSRC(:,:,IB+1) - PSRC(:,:,IB+2))**2 ! First negative smoothness indicator
+ZBNEG2(:,:,IB+1) = (PSRC(:,:,IB)   - PSRC(:,:,IB+1))**2 ! Second negative smoothness indicator
+!
+ZOMP1(:,:,IB+1) = 1./3. / (ZEPS + ZBPOS1(:,:,IB+1))**2 ! First positive non-normalized weight
+ZOMP2(:,:,IB+1) = 2./3. / (ZEPS + ZBPOS2(:,:,IB+1))**2 ! Second positive non-normalized weight
+ZOMN1(:,:,IB+1) = 1./3. / (ZEPS + ZBNEG1(:,:,IB+1))**2 ! First negative non-normalized weight
+ZOMN2(:,:,IB+1) = 2./3. / (ZEPS + ZBNEG2(:,:,IB+1))**2 ! Second negative non-normalized weight
+! 
+PR(:,:,IB+1) = (ZOMP2(:,:,IB+1)/(ZOMP1(:,:,IB+1)+ZOMP2(:,:,IB+1)) * ZFPOS2(:,:,IB+1)  &
+              + ZOMP1(:,:,IB+1)/(ZOMP1(:,:,IB+1)+ZOMP2(:,:,IB+1)) * ZFPOS1(:,:,IB+1)) * &
+    (0.5+SIGN(0.5,PRWCT(:,:,IB+1) ))           &
+             + (ZOMN2(:,:,IB+1)/(ZOMN1(:,:,IB+1)+ZOMN2(:,:,IB+1)) * ZFNEG2(:,:,IB+1)    &
+              + ZOMN1(:,:,IB+1)/(ZOMN1(:,:,IB+1)+ZOMN2(:,:,IB+1)) * ZFNEG1(:,:,IB+1)) * &
+    (0.5-SIGN(0.5,PRWCT(:,:,IB+1) )) ! Total flux
+! 
+!-------------------------------------------------------------------------------
+!*       1.3.   Top border
+!               ---------------------
 !
-! WENO weights
+!---------------------------------------------------------------------------
+! Open, or Wall, or Nest boundary condition => WENO order reduction
+!---------------------------------------------------------------------------
 !
-ZOMP1(:,:,IB+2:IT-1) = ZGAMMA1 / (ZEPS + ZBPOS1(:,:,IB+2:IT-1))**2
-ZOMP2(:,:,IB+2:IT-1) = ZGAMMA2 / (ZEPS + ZBPOS2(:,:,IB+2:IT-1))**2
-ZOMP3(:,:,IB+2:IT-1) = ZGAMMA3 / (ZEPS + ZBPOS3(:,:,IB+2:IT-1))**2
-ZOMN1(:,:,IB+2:IT-1) = ZGAMMA1 / (ZEPS + ZBNEG1(:,:,IB+2:IT-1))**2
-ZOMN2(:,:,IB+2:IT-1) = ZGAMMA2 / (ZEPS + ZBNEG2(:,:,IB+2:IT-1))**2
-ZOMN3(:,:,IB+2:IT-1) = ZGAMMA3 / (ZEPS + ZBNEG3(:,:,IB+2:IT-1))**2
-!
-ZOMP1(:,:,IB+1) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,:,IB+1))**2
-ZOMP2(:,:,IB+1) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,:,IB+1))**2
-ZOMN1(:,:,IB+1) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,:,IB+1))**2
-ZOMN2(:,:,IB+1) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,:,IB+1))**2
-ZOMP1(:,:,  IT) = ZGAMMA1_PRIM / (ZEPS + ZBPOS1(:,:,  IT))**2
-ZOMP2(:,:,  IT) = ZGAMMA2_PRIM / (ZEPS + ZBPOS2(:,:,  IT))**2
-ZOMN1(:,:,  IT) = ZGAMMA1_PRIM / (ZEPS + ZBNEG1(:,:,  IT))**2
-ZOMN2(:,:,  IT) = ZGAMMA2_PRIM / (ZEPS + ZBNEG2(:,:,  IT))**2 
-!
-PR(:,:,IB+2:IT-1) = (ZOMP1(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ &
-                    ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) * &
-                    ZFPOS1(:,:,IB+2:IT-1)                        &
-                   + ZOMP2(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ &
-                   ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) *  &
-                   ZFPOS2(:,:,IB+2:IT-1)                         &
-                   + ZOMP3(:,:,IB+2:IT-1)/(ZOMP1(:,:,IB+2:IT-1)+ &
-                   ZOMP2(:,:,IB+2:IT-1)+ZOMP3(:,:,IB+2:IT-1)) *  &
-                   ZFPOS3(:,:,IB+2:IT-1))                        &
-                   * (0.5+SIGN(0.5,PRWCT(:,:,IB+2:IT-1)))        &
-                  + (ZOMN1(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ &
-                   ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) *  &
-                   ZFNEG1(:,:,IB+2:IT-1)                         &
-                   + ZOMN2(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ &
-                   ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) *  &
-                   ZFNEG2(:,:,IB+2:IT-1)                         &
-                   + ZOMN3(:,:,IB+2:IT-1)/(ZOMN1(:,:,IB+2:IT-1)+ &
-                   ZOMN2(:,:,IB+2:IT-1)+ZOMN3(:,:,IB+2:IT-1)) *  &
-                   ZFNEG3(:,:,IB+2:IT-1))                        &
-                   * (0.5-SIGN(0.5,PRWCT(:,:,IB+2:IT-1) )) 
-!
-PR(:,:,IB+1) = (ZOMP2(:,:,IB+1)/(ZOMP1(:,:,IB+1)+ZOMP2(:,:,IB+1)) * &
-                ZFPOS2(:,:,IB+1)                                    &
-              + ZOMP1(:,:,IB+1)/(ZOMP1(:,:,IB+1)+ZOMP2(:,:,IB+1)) * &
-                ZFPOS1(:,:,IB+1)) * (0.5+SIGN(0.5,PRWCT(:,:,IB+1) ))&
-             + (ZOMN2(:,:,IB+1)/(ZOMN1(:,:,IB+1)+ZOMN2(:,:,IB+1)) * &
-                ZFNEG2(:,:,IB+1)                                    &
-              + ZOMN1(:,:,IB+1)/(ZOMN1(:,:,IB+1)+ZOMN2(:,:,IB+1)) * &
-                ZFNEG1(:,:,IB+1)) * (0.5-SIGN(0.5,PRWCT(:,:,IB+1) ))
+! WENO scheme order 1, IT+1
+PR(:,:,IT+1) = PSRC(:,:,IT  ) * (0.5+SIGN(0.5,PRWCT(:,:,IT+1) )) &
+             + PSRC(:,:,IT+1) * (0.5-SIGN(0.5,PRWCT(:,:,IT+1) ))
 !
+! WENO scheme order 3, IT
+ZFPOS1(:,:,IT) = 0.5 * (3.0*PSRC(:,:,IT-1) - PSRC(:,:,IT-2)) ! First positive flux
+ZFPOS2(:,:,IT) = 0.5 * ( PSRC(:,:,IT-1) + PSRC(:,:,IT)) ! Second positive flux
+ZBPOS1(:,:,IT) = (PSRC(:,:,IT-1) - PSRC(:,:,IT-2))**2 ! First positive smoothness indicator
+ZBPOS2(:,:,IT) = (PSRC(:,:,IT)   - PSRC(:,:,IT-1))**2 ! Second positive smoothness indicator
+!
+ZFNEG1(:,:,IT) = 0.5 * (3.0*PSRC(:,:,IT)   - PSRC(:,:,IT+1)) ! First negative flux
+ZFNEG2(:,:,IT) = 0.5 * ( PSRC(:,:,IT-1) + PSRC(:,:,IT)) ! Second negative flux
+ZBNEG1(:,:,IT) = (PSRC(:,:,IT)   - PSRC(:,:,IT+1))**2 ! First negative smoothness indicator
+ZBNEG2(:,:,IT) = (PSRC(:,:,IT-1) - PSRC(:,:,IT))**2  ! Second negative smoothness indicator
+!
+ZOMP1(:,:,IT) = 1./3. / (ZEPS + ZBPOS1(:,:,IT))**2 ! First positive non-normalized weight
+ZOMP2(:,:,IT) = 2./3. / (ZEPS + ZBPOS2(:,:,IT))**2 ! Second positive non-normalized weight
+ZOMN1(:,:,IT) = 1./3. / (ZEPS + ZBNEG1(:,:,IT))**2 ! First negative non-normalized weight
+ZOMN2(:,:,IT) = 2./3. / (ZEPS + ZBNEG2(:,:,IT))**2 ! Second negative non-normalized weight
+! 
 PR(:,:,IT) = (ZOMP2(:,:,IT)/(ZOMP1(:,:,IT)+ZOMP2(:,:,IT)) * ZFPOS2(:,:,IT)     &
             + ZOMP1(:,:,IT)/(ZOMP1(:,:,IT)+ZOMP2(:,:,IT)) * ZFPOS1(:,:,IT)) *  &
             (0.5+SIGN(0.5,PRWCT(:,:,IT) ))                                     &
            + (ZOMN2(:,:,IT)/(ZOMN1(:,:,IT)+ZOMN2(:,:,IT)) * ZFNEG2(:,:,IT)     &
             + ZOMN1(:,:,IT)/(ZOMN1(:,:,IT)+ZOMN2(:,:,IT)) * ZFNEG1(:,:,IT)) *  &
-            (0.5-SIGN(0.5,PRWCT(:,:,IT) ))
-!
-PR(:,:,IB) = PSRC(:,:,IB-1) * (0.5+SIGN(0.5,PRWCT(:,:,IB) )) &
-           + PSRC(:,:,IB  ) * (0.5-SIGN(0.5,PRWCT(:,:,IB) ))
-!
-PR(:,:,IT+1) = PSRC(:,:,IT  ) * (0.5+SIGN(0.5,PRWCT(:,:,IT+1) )) &
-             + PSRC(:,:,IT+1) * (0.5-SIGN(0.5,PRWCT(:,:,IT+1) ))
-!
-!PR(:,:,IB-1) = - 999.
+            (0.5-SIGN(0.5,PRWCT(:,:,IT) ))  ! Total flux
 !
-PR = PR * PRWCT
+PR = PR * PRWCT ! Add contravariant flux
 !
 END FUNCTION WENO_K_3_MZ