diff --git a/Registry/Registry.EM_COMMON b/Registry/Registry.EM_COMMON
index 710627c300..a65fa49692 100644
--- a/Registry/Registry.EM_COMMON
+++ b/Registry/Registry.EM_COMMON
@@ -1192,6 +1192,7 @@ state logical just_read_auxinput4  -      misc      -         -     r    "we_jus
 state logical just_read_boundary   -      misc      -         -     r    "we_just_d01_LBC"           "1=BOUNDARY  ALARM RINGING, 0=NO BOUNDARY  ALARM"  "-"
 state   real    mf_fft         -       misc         -         -     r        "mf_fft"                "Mass point map factor at equatorward FFT filter location"  ""
 state   real    p_top          -       misc         -         -     irh       "p_top"                "PRESSURE TOP OF THE MODEL"  "Pa"
+state logical got_var_sso	-	misc	    -	      -     i02r  "got_var_sso"		     "whether VAR_SSO was included in WPS output (beginning V3.4)" ""
 
 #BSINGH - Adding all these variables for CuP scheme[any var before t00]
 state   real    lat_ll_t       -       dyn_em       -         -     ir       "lat_ll_t"              "latitude lower left, temp point" "degrees"
diff --git a/dyn_em/module_initialize_real.F b/dyn_em/module_initialize_real.F
index 8333357093..7ad465d565 100644
--- a/dyn_em/module_initialize_real.F
+++ b/dyn_em/module_initialize_real.F
@@ -3776,6 +3776,21 @@ SUBROUTINE init_domain_rk ( grid &
 !     CALL wrf_debug ( 0 , '   DONE routine to add snow in high mountain peaks')
 !+---+-----------------------------------------------------------------+
 
+! checking whether var_sso exists in the domain
+      ! if so, we set got_var_sso flag to true.  This is later used in external/RSL_LITE/module_dm.F
+      ! to check for this, when the topo_wind option is used.
+      grid%got_var_sso = .FALSE.
+      DO j=jts,MIN(jde-1,jte)
+         DO i=its,MIN(ide-1,ite)
+           IF ( skip_middle_points_t ( ids , ide , jds , jde , i , j , em_width , hold_ups ) ) CYCLE
+               IF(grid%var_sso(i,j) .NE. 0) THEN
+                    grid%got_var_sso = .true.
+               ENDIF
+         END DO
+      END DO
+#if ( defined(DM_PARALLEL)  &&   ! defined(STUBMPI) )
+      grid%got_var_sso = wrf_dm_lor_logical ( grid%got_var_sso )
+#endif
 
 #ifdef DM_PARALLEL
 #   include "HALO_EM_INIT_1.inc"
diff --git a/dyn_em/start_em.F b/dyn_em/start_em.F
index e842b68ec3..756b8744e4 100644
--- a/dyn_em/start_em.F
+++ b/dyn_em/start_em.F
@@ -204,6 +204,10 @@ SUBROUTINE start_domain_em ( grid, allowed_to_read &
 ! here we check to see if the boundary conditions are set properly
 
    CALL boundary_condition_check( config_flags, bdyzone, error, grid%id )
+! make sure that topo_wind option has var_sso data available
+    IF ((config_flags%topo_wind .EQ. 1) .AND. (.NOT. grid%got_var_sso)) THEN
+      CALL wrf_error_fatal ("topo_wind requires VAR_SSO data")
+    ENDIF
 
 !kludge - need to stop CG from resetting precip and phys tendencies to zero
 !         when we are in here due to a nest being spawned, we want to still
diff --git a/external/RSL_LITE/module_dm.F b/external/RSL_LITE/module_dm.F
index cc438f96dc..8312280d68 100644
--- a/external/RSL_LITE/module_dm.F
+++ b/external/RSL_LITE/module_dm.F
@@ -1478,6 +1478,37 @@ INTEGER FUNCTION wrf_dm_bxor_integer ( inval )
 #endif
    END FUNCTION wrf_dm_bxor_integer
 
+
+LOGICAL FUNCTION wrf_dm_lor_logical ( inval )
+      IMPLICIT NONE
+#ifndef STUBMPI
+      LOGICAL inval, retval
+      INTEGER comm, ierr
+      CALL wrf_get_dm_communicator(comm)
+      CALL mpi_allreduce ( inval, retval , 1, MPI_LOGICAL, MPI_LAND, comm, ierr )
+      wrf_dm_lor_logical = retval
+#else
+      LOGICAL inval
+      wrf_dm_lor_logical = inval
+#endif
+   END FUNCTION wrf_dm_lor_logical
+
+
+LOGICAL FUNCTION wrf_dm_land_logical ( inval )
+      IMPLICIT NONE
+#ifndef STUBMPI
+      LOGICAL inval, retval
+      INTEGER comm, ierr
+      CALL wrf_get_dm_communicator(comm)
+      CALL mpi_allreduce ( inval, retval , 1, MPI_LOGICAL, MPI_LAND, comm, ierr )
+      wrf_dm_land_logical = retval
+#else
+      LOGICAL inval
+      wrf_dm_land_logical = inval
+#endif
+   END FUNCTION wrf_dm_land_logical
+
+
    SUBROUTINE wrf_dm_maxval_real ( val, idex, jdex )
 # ifndef STUBMPI
       use mpi