diff --git a/parm/config/gefs/config.base b/parm/config/gefs/config.base
index 07664f15ff..bc37c5abbc 100644
--- a/parm/config/gefs/config.base
+++ b/parm/config/gefs/config.base
@@ -137,6 +137,13 @@ export DO_AERO="NO"
 export WAVE_CDUMP="" # When to include wave suite: gdas, gfs, or both
 export DOBNDPNT_WAVE="NO" # The GEFS buoys file does not currently have any boundary points
 export FRAC_GRID=".true."
+export DO_NEST="NO" # Whether to run a global-nested domain
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  export ntiles=7
+  export NEST_OUTPUT_GRID="regional_latlon"
+else
+  export ntiles=6
+fi
 
 # Set operational resolution
 export OPS_RES="C768" # Do not change
diff --git a/parm/config/gfs/config.base b/parm/config/gfs/config.base
index 5a58c75220..ab35f717cb 100644
--- a/parm/config/gfs/config.base
+++ b/parm/config/gfs/config.base
@@ -184,6 +184,13 @@ export DO_AERO="NO"
 export WAVE_CDUMP="" # When to include wave suite: gdas, gfs, or both
 export DOBNDPNT_WAVE="NO"
 export FRAC_GRID=".true."
+export DO_NEST="NO" # Whether to run a global-nested domain
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  export ntiles=7
+  export NEST_OUTPUT_GRID="regional_latlon"
+else
+  export ntiles=6
+fi
 
 # Set operational resolution
 export OPS_RES="C768" # Do not change # TODO: Why is this needed and where is it used?
diff --git a/parm/config/gfs/config.fcst b/parm/config/gfs/config.fcst
index 14621307f5..63273e0fe4 100644
--- a/parm/config/gfs/config.fcst
+++ b/parm/config/gfs/config.fcst
@@ -254,6 +254,9 @@ export DO_SKEB=${DO_SKEB:-"NO"}
 export DO_SHUM=${DO_SHUM:-"NO"}
 export DO_LAND_PERT=${DO_LAND_PERT:-"NO"}
 export DO_CA=${DO_CA:-"YES"}
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  export DO_CA="NO"  # CA does not work with nesting.
+fi
 
 #coupling settings
 export cplmode="ufs.frac"
diff --git a/parm/config/gfs/config.resources b/parm/config/gfs/config.resources
index aafe7b0967..89953c7b84 100644
--- a/parm/config/gfs/config.resources
+++ b/parm/config/gfs/config.resources
@@ -606,6 +606,13 @@ case ${step} in
         [[ "${DO_ICE}" == "YES" ]] && nthreads_cice6=1
       fi
 
+      if (( ntiles > 6 )); then
+        export layout_x_nest=${layout_x_nest:-10}
+        export layout_y_nest=${layout_y_nest:-10}
+        export npx_nest=${npx_nest:-1441}
+        export npy_nest=${npy_nest:-961}
+      fi
+
       # PETS for the atmosphere dycore
       (( FV3PETS = ntasks_fv3 * nthreads_fv3 ))
       echo "FV3 using (nthreads, PETS) = (${nthreads_fv3}, ${FV3PETS})"
diff --git a/parm/config/gfs/config.stage_ic b/parm/config/gfs/config.stage_ic
index 63d0e4a5cf..9956e8af6a 100644
--- a/parm/config/gfs/config.stage_ic
+++ b/parm/config/gfs/config.stage_ic
@@ -38,4 +38,8 @@ case "${CASE}" in
     ;;
 esac
 
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  export CPL_ATMIC="GLOBAL-NEST_${CASE}"
+fi
+
 echo "END: config.stage_ic"
diff --git a/parm/config/gfs/config.ufs b/parm/config/gfs/config.ufs
index 7cec5a0822..e37e46cf70 100644
--- a/parm/config/gfs/config.ufs
+++ b/parm/config/gfs/config.ufs
@@ -68,6 +68,22 @@ if [[ "${skip_mom6}" == "false" ]] || [[ "${skip_cice6}" == "false" ]] || [[ "${
   skip_mediator=false
 fi
 
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  # Describe nest location, interaction with parent, etc.
+  export grid_type=0
+  export stretch_fac=1.0001
+  export TARGET_LAT=32.5
+  export TARGET_LON=-135.0
+  export NEST_LON1=-195.000000
+  export NEST_LAT1=-7.500000
+  export NEST_LON2=-75.000000
+  export NEST_LAT2=72.500000
+  export twowaynest=${twowaynest:-.true.}
+else
+  # No nest.
+  export grid_type=-1
+fi
+
 # (Standard) Model resolution dependent variables
 case "${fv3_res}" in
     "C48")
@@ -89,76 +105,158 @@ case "${fv3_res}" in
         export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=1
         ;;
     "C96")
-        export DELTIM=600
-        export layout_x=2
-        export layout_y=2
-        export layout_x_gfs=2
-        export layout_y_gfs=2
-        export nthreads_fv3=1
-        export nthreads_fv3_gfs=1
-        export nthreads_ufs=1
-        export nthreads_ufs_gfs=1
-        export cdmbgwd="0.14,1.8,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
-        export cdmbgwd_gsl="20.0,2.5,1.0,1.0"   # settings for GSL drag suite
-        export knob_ugwp_tauamp=3.0e-3      # setting for UGWPv1 non-stationary GWD
-        export WRITE_GROUP=1
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=1
-        export WRITE_GROUP_GFS=1
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=1
+        if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+          export DELTIM=450
+          export layout_x_gfs=4
+          export layout_y_gfs=4
+          export layout_x_nest=12
+          export layout_y_nest=10
+          export nest_refine=4
+          export nest_ioffset=4
+          export nest_joffset=9
+          export npx_nest=361
+          export npy_nest=241
+          export NEST_DLON=0.25
+          export NEST_DLAT=0.25
+          export WRITE_GROUP=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=2
+          export WRITE_GROUP_GFS=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=2
+        else
+          export DELTIM=600
+          export layout_x=2
+          export layout_y=2
+          export layout_x_gfs=2
+          export layout_y_gfs=2
+          export nthreads_fv3=1
+          export nthreads_fv3_gfs=1
+          export nthreads_ufs=1
+          export nthreads_ufs_gfs=1
+          export cdmbgwd="0.14,1.8,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
+          export cdmbgwd_gsl="20.0,2.5,1.0,1.0"   # settings for GSL drag suite
+          export knob_ugwp_tauamp=3.0e-3      # setting for UGWPv1 non-stationary GWD
+          export WRITE_GROUP=1
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=1
+          export WRITE_GROUP_GFS=1
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=1
+        fi
         ;;
     "C192")
-        export DELTIM=450
-        export layout_x=4
-        export layout_y=6
-        export layout_x_gfs=4
-        export layout_y_gfs=6
-        export nthreads_fv3=1
-        export nthreads_fv3_gfs=2
-        export nthreads_ufs=1
-        export nthreads_ufs_gfs=2
-        export cdmbgwd="0.23,1.5,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
-        export cdmbgwd_gsl="10.0,3.5,1.0,1.0"   # settings for GSL drag suite
-        export knob_ugwp_tauamp=1.5e-3      # setting for UGWPv1 non-stationary GWD
-        export WRITE_GROUP=1
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
-        export WRITE_GROUP_GFS=2
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=5
+        if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+          export DELTIM=225
+          export layout_x_gfs=5
+          export layout_y_gfs=6
+          export layout_x_nest=15
+          export layout_y_nest=25
+          export nest_refine=4
+          export nest_ioffset=7
+          export nest_joffset=19
+          export npx_nest=721
+          export npy_nest=481
+          export NEST_DLON=0.125
+          export NEST_DLAT=0.125
+          export WRITE_GROUP=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=15
+          export WRITE_GROUP_GFS=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=15
+        else
+          export DELTIM=450
+          export layout_x=4
+          export layout_y=6
+          export layout_x_gfs=4
+          export layout_y_gfs=6
+          export nthreads_fv3=1
+          export nthreads_fv3_gfs=2
+          export nthreads_ufs=1
+          export nthreads_ufs_gfs=2
+          export cdmbgwd="0.23,1.5,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
+          export cdmbgwd_gsl="10.0,3.5,1.0,1.0"   # settings for GSL drag suite
+          export knob_ugwp_tauamp=1.5e-3      # setting for UGWPv1 non-stationary GWD
+          export WRITE_GROUP=1
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
+          export WRITE_GROUP_GFS=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=5
+        fi
         ;;
     "C384")
-        export DELTIM=300
-        export layout_x=8
-        export layout_y=8
-        export layout_x_gfs=8
-        export layout_y_gfs=8
-        export nthreads_fv3=2
-        export nthreads_fv3_gfs=2
-        export nthreads_ufs=2
-        export nthreads_ufs_gfs=2
-        export cdmbgwd="1.1,0.72,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
-        export cdmbgwd_gsl="5.0,5.0,1.0,1.0"   # settings for GSL drag suite
-        export knob_ugwp_tauamp=0.8e-3      # setting for UGWPv1 non-stationary GWD
-        export WRITE_GROUP=4
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
-        export WRITE_GROUP_GFS=4
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=10
+        if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+          export DELTIM=150
+          export layout_x=8
+          export layout_y=8
+          export layout_x_gfs=8
+          export layout_y_gfs=8
+          export layout_x_nest=34
+          export layout_y_nest=24
+          export nest_refine=4
+          export nest_ioffset=13
+          export nest_joffset=37
+          export npx_nest=1441
+          export npy_nest=961
+          export NEST_DLON=0.0625
+          export NEST_DLAT=0.0625
+          export WRITE_GROUP=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=20
+          export WRITE_GROUP_GFS=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=20
+        else
+          export DELTIM=300
+          export layout_x=8
+          export layout_y=8
+          export layout_x_gfs=8
+          export layout_y_gfs=8
+          export nthreads_fv3=2
+          export nthreads_fv3_gfs=2
+          export nthreads_ufs=2
+          export nthreads_ufs_gfs=2
+          export cdmbgwd="1.1,0.72,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
+          export cdmbgwd_gsl="5.0,5.0,1.0,1.0"   # settings for GSL drag suite
+          export knob_ugwp_tauamp=0.8e-3      # setting for UGWPv1 non-stationary GWD
+          export WRITE_GROUP=4
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
+          export WRITE_GROUP_GFS=4
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=10
+        fi
         ;;
     "C768")
-        export DELTIM=150
-        export layout_x=8
-        export layout_y=12
-        export layout_x_gfs=12
-        export layout_y_gfs=16
-        export nthreads_fv3=4
-        export nthreads_fv3_gfs=4
-        export nthreads_ufs=4
-        export nthreads_ufs_gfs=4
-        export cdmbgwd="4.0,0.15,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
-        export cdmbgwd_gsl="2.5,7.5,1.0,1.0"   # settings for GSL drag suite
-        export knob_ugwp_tauamp=0.5e-3      # setting for UGWPv1 non-stationary GWD
-        export WRITE_GROUP=2
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
-        export WRITE_GROUP_GFS=4
-        export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=20 #Note this should be 10 for WCOSS2
+        if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+          export DELTIM=75
+          export layout_x=16
+          export layout_y=10
+          export layout_x_gfs=16
+          export layout_y_gfs=10
+          export layout_x_nest=48
+          export layout_y_nest=45
+          export nthreads_fv3=2
+          export nthreads_fv3_gfs=2
+          export nest_refine=4
+          export nest_ioffset=24
+          export nest_joffset=72
+          export npx_nest=2881
+          export npy_nest=1921
+          export NEST_DLON=0.0325
+          export NEST_DLAT=0.0325
+          export WRITE_GROUP=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=90
+          export WRITE_GROUP_GFS=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=90
+        else
+          export DELTIM=150
+          export layout_x=8
+          export layout_y=12
+          export layout_x_gfs=12
+          export layout_y_gfs=16
+          export nthreads_fv3=4
+          export nthreads_fv3_gfs=4
+          export nthreads_ufs=4
+          export nthreads_ufs_gfs=4
+          export cdmbgwd="4.0,0.15,1.0,1.0"  # mountain blocking, ogwd, cgwd, cgwd src scaling
+          export cdmbgwd_gsl="2.5,7.5,1.0,1.0"   # settings for GSL drag suite
+          export knob_ugwp_tauamp=0.5e-3      # setting for UGWPv1 non-stationary GWD
+          export WRITE_GROUP=2
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE=10
+          export WRITE_GROUP_GFS=4
+          export WRTTASK_PER_GROUP_PER_THREAD_PER_TILE_GFS=20 #Note this should be 10 for WCOSS2
+        fi
         ;;
     "C1152")
         export DELTIM=120
@@ -209,6 +307,9 @@ export WRTTASK_PER_GROUP_PER_THREAD_GFS
 
 (( ntasks_fv3 = layout_x * layout_y * 6 ))
 (( ntasks_fv3_gfs = layout_x_gfs * layout_y_gfs * 6 ))
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  (( ntasks_fv3_gfs += layout_x_nest * layout_y_nest ))
+fi
 export ntasks_fv3
 export ntasks_fv3_gfs
 
@@ -241,7 +342,11 @@ export cplice=".false."
 export cplchm=".false."
 export cplwav=".false."
 export cplwav2atm=".false."
-export CCPP_SUITE="${CCPP_SUITE:-FV3_GFS_v17_p8_ugwpv1}"
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  export CCPP_SUITE="${CCPP_SUITE:-FV3_global_nest_v1}"
+else
+  export CCPP_SUITE="${CCPP_SUITE:-FV3_GFS_v17_p8_ugwpv1}"
+fi
 model_list="atm"
 
 # Mediator specific settings
diff --git a/scripts/exglobal_stage_ic.sh b/scripts/exglobal_stage_ic.sh
index 1a15ceb465..d941fa10b4 100755
--- a/scripts/exglobal_stage_ic.sh
+++ b/scripts/exglobal_stage_ic.sh
@@ -42,9 +42,13 @@ for MEMDIR in "${MEMDIR_ARRAY[@]}"; do
       err=$((err + rc))
     done
     for ftype in ca_data fv_core.res fv_srf_wnd.res fv_tracer.res phy_data sfc_data; do
-      for ((tt = 1; tt <= 6; tt++)); do
+      for ((tt = 1; tt <= ntiles; tt++)); do
         src="${BASE_CPLIC}/${CPL_ATMIC:-}/${PDY}${cyc}/${MEMDIR}/atmos/${PDY}.${cyc}0000.${ftype}.tile${tt}.nc"
-        tgt="${COM_ATMOS_RESTART_PREV}/${PDY}.${cyc}0000.${ftype}.tile${tt}.nc"
+        if (( tt > 6 )) ; then
+            tgt="${COM_ATMOS_RESTART_PREV}/${PDY}.${cyc}0000.${ftype}.nest0$((tt-5)).tile${tt}.nc"
+        else
+            tgt="${COM_ATMOS_RESTART_PREV}/${PDY}.${cyc}0000.${ftype}.tile${tt}.nc"
+        fi
         ${NCP} "${src}" "${tgt}"
         rc=$?
         ((rc != 0)) && error_message "${src}" "${tgt}" "${rc}"
@@ -62,7 +66,7 @@ for MEMDIR in "${MEMDIR_ARRAY[@]}"; do
     ((rc != 0)) && error_message "${src}" "${tgt}" "${rc}"
     err=$((err + rc))
     for ftype in gfs_data sfc_data; do
-      for ((tt = 1; tt <= 6; tt++)); do
+      for ((tt = 1; tt <= ntiles; tt++)); do
         src="${BASE_CPLIC}/${CPL_ATMIC:-}/${PDY}${cyc}/${MEMDIR}/atmos/${ftype}.tile${tt}.nc"
         tgt="${COM_ATMOS_INPUT}/${ftype}.tile${tt}.nc"
         ${NCP} "${src}" "${tgt}"
@@ -70,6 +74,9 @@ for MEMDIR in "${MEMDIR_ARRAY[@]}"; do
         ((rc != 0)) && error_message "${src}" "${tgt}" "${rc}"
         err=$((err + rc))
       done
+      if (( ntiles > 6 )); then
+        ${NLN} "${COM_ATMOS_INPUT}/${ftype}.tile7.nc" "${COM_ATMOS_INPUT}/${ftype}.nest02.tile7.nc"
+      fi
     done
   fi
 
diff --git a/sorc/link_workflow.sh b/sorc/link_workflow.sh
index 7106d1ed79..2a9d9d04db 100755
--- a/sorc/link_workflow.sh
+++ b/sorc/link_workflow.sh
@@ -178,7 +178,7 @@ done
 
 # Link these templates from ufs-weather-model
 cd "${HOMEgfs}/parm/ufs" || exit 1
-declare -a ufs_templates=("model_configure.IN" \
+declare -a ufs_templates=("model_configure.IN" "model_configure_nest.IN"\
                           "MOM_input_025.IN" "MOM_input_050.IN" "MOM_input_100.IN" "MOM_input_500.IN" \
                           "MOM6_data_table.IN" \
                           "ice_in.IN" \
diff --git a/ush/forecast_postdet.sh b/ush/forecast_postdet.sh
index fd1ef9a078..8ea556055d 100755
--- a/ush/forecast_postdet.sh
+++ b/ush/forecast_postdet.sh
@@ -180,6 +180,10 @@ EOF
       if [[ "${WRITE_DOPOST}" == ".true." ]]; then
         ${NLN} "${COM_ATMOS_MASTER}/${RUN}.t${cyc}z.master.grb2f${FH3}" "GFSPRS.GrbF${FH2}"
         ${NLN} "${COM_ATMOS_MASTER}/${RUN}.t${cyc}z.sfluxgrbf${FH3}.grib2" "GFSFLX.GrbF${FH2}"
+        if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+          ${NLN} "${COM_ATMOS_MASTER}/${RUN}.t${cyc}z.nest.grb2f${FH3}" "GFSPRS.GrbF${FH2}.nest02"
+          ${NLN} "${COM_ATMOS_MASTER}/${RUN}.t${cyc}z.nest.sfluxgrbf${FH3}.grib2" "GFSFLX.GrbF${FH2}.nest02"
+        fi
       fi
     done
   else  # TODO: Is this even valid anymore?
@@ -201,7 +205,14 @@ FV3_nml() {
   source "${USHgfs}/parsing_namelists_FV3.sh"
   source "${USHgfs}/parsing_model_configure_FV3.sh"
 
-  FV3_namelists
+  # Call the appropriate namelist functions
+  if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+    source "${USHgfs}/parsing_namelists_FV3_nest.sh"
+    FV3_namelists_nest global
+    FV3_namelists_nest nest
+  else
+    FV3_namelists
+  fi
   FV3_model_configure
 
   echo "SUB ${FUNCNAME[0]}: FV3 name lists and model configure file created"
diff --git a/ush/forecast_predet.sh b/ush/forecast_predet.sh
index a5944d5bd2..c300067ce9 100755
--- a/ush/forecast_predet.sh
+++ b/ush/forecast_predet.sh
@@ -117,9 +117,6 @@ FV3_predet(){
   IAUFHRS=${IAUFHRS:-0}
   IAU_DELTHRS=${IAU_DELTHRS:-0}
 
-  # Model config options
-  ntiles=6
-
   #------------------------------------------------------------------
   # changeable parameters
   # dycore definitions
@@ -242,9 +239,16 @@ FV3_predet(){
 
   # Conserve total energy as heat globally
   consv_te=${consv_te:-1.} # range 0.-1., 1. will restore energy to orig. val. before physics
+  if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+    consv_te=0
+    k_split=${k_split:-1}
+    k_split_nest=${k_split_nest:-4}
+  else
+    consv_te=${consv_te:-1.} # range 0.-1., 1. will restore energy to orig. val. before physics
+    k_split=${k_split:-2}
+  fi
 
   # time step parameters in FV3
-  k_split=${k_split:-2}
   n_split=${n_split:-5}
 
   if [[ "${MONO:0:4}" == "mono" ]]; then  # monotonic options
@@ -370,6 +374,13 @@ FV3_predet(){
     ${NCP} "${FIXgfs}/ugwd/${CASE}/${CASE}_oro_data_ls.tile${tt}.nc"          "${DATA}/INPUT/oro_data_ls.tile${tt}.nc"
     ${NCP} "${FIXgfs}/ugwd/${CASE}/${CASE}_oro_data_ss.tile${tt}.nc"          "${DATA}/INPUT/oro_data_ss.tile${tt}.nc"
   done
+  if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+    ${NLN} "${DATA}/INPUT/oro_data.tile7.nc" "${DATA}/INPUT/oro_data.nest02.tile7.nc"
+    ${NLN} "${DATA}/INPUT/${CASE}_grid.tile7.nc"     "${DATA}/INPUT/${CASE}_grid.nest02.tile7.nc"
+    ${NLN} "${DATA}/INPUT/${CASE}_grid.tile7.nc"     "${DATA}/INPUT/grid.nest02.tile7.nc"
+    ${NLN} "${DATA}/INPUT/oro_data_ls.tile7.nc" "${DATA}/INPUT/oro_data_ls.nest02.tile7.nc"
+    ${NLN} "${DATA}/INPUT/oro_data_ss.tile7.nc" "${DATA}/INPUT/oro_data_ss.nest02.tile7.nc"
+  fi
 
   # NoahMP table
   local noahmptablefile="${PARMgfs}/ufs/noahmptable.tbl"
diff --git a/ush/parsing_model_configure_FV3.sh b/ush/parsing_model_configure_FV3.sh
index 59d9fb6910..7d64ab38f9 100755
--- a/ush/parsing_model_configure_FV3.sh
+++ b/ush/parsing_model_configure_FV3.sh
@@ -52,7 +52,13 @@ local OUTPUT_FH=${FV3_OUTPUT_FH}
 local IAU_OFFSET=${IAU_OFFSET:-0}
 
 # Ensure the template exists
-template="${PARMgfs}/ufs/model_configure.IN"
+if [[ "${DO_NEST:-NO}" == "YES" ]] ; then
+  local NEST_IMO=${npx_nest}
+  local NEST_JMO=${npy_nest}
+  template="${PARMgfs}/ufs/model_configure_nest.IN"
+else
+  template="${PARMgfs}/ufs/model_configure.IN"
+fi
 if [[ ! -f ${template} ]]; then
   echo "FATAL ERROR: template '${template}' does not exist, ABORT!"
   exit 1
diff --git a/ush/parsing_namelists_FV3_nest.sh b/ush/parsing_namelists_FV3_nest.sh
new file mode 100755
index 0000000000..2f99a1cdf5
--- /dev/null
+++ b/ush/parsing_namelists_FV3_nest.sh
@@ -0,0 +1,832 @@
+#! /usr/bin/env bash
+
+# parsing namelist of FV3, diag_table, etc.
+
+# Disable variable not used warnings and 'masking return value' warnings
+# shellcheck disable=SC2034
+# shellcheck disable=SC2312
+FV3_namelists_nest(){
+
+# First argument tells us which namelist we're writing:
+#   global = writing input.nml for running global with a nest
+#   nest   = writing input_nest02.nml for running the nest
+namelist_mode="${1:-global}"
+
+if [[ "${namelist_mode}" == "nest" ]] ; then
+  nml_file=input_nest02.nml
+  only_input_nml="YES"
+else
+  nml_file=input.nml
+  only_input_nml="NO"
+fi
+
+# setup the tables
+DIAG_TABLE=${DIAG_TABLE:-${PARMgfs}/ufs/fv3/diag_table}
+DIAG_TABLE_APPEND=${DIAG_TABLE_APPEND:-${PARMgfs}/ufs/fv3/diag_table_aod}
+DATA_TABLE=${DATA_TABLE:-${PARMgfs}/ufs/MOM6_data_table.IN}
+FIELD_TABLE=${FIELD_TABLE:-${PARMgfs}/ufs/fv3/field_table}
+
+# set cdmbgwd
+if (( gwd_opt == 2 )) && [[ ${do_gsl_drag_ls_bl} == ".true." ]]; then
+  cdmbgwd=${cdmbgwd_gsl}
+fi
+
+# ensure non-prognostic tracers are set
+dnats=${dnats:-0}
+
+if [[ "${only_input_nml:-NO}" == "NO" ]] ; then
+# build the diag_table
+{
+echo "UFS_Weather_Model_Forecast"
+if [[ "${DOIAU}" = "YES" ]]; then
+  echo "${previous_cycle:0:4} ${previous_cycle:4:2} ${previous_cycle:6:2} ${previous_cycle:8:2} 0 0"
+else
+  echo "${current_cycle:0:4} ${current_cycle:4:2} ${current_cycle:6:2} ${current_cycle:8:2} 0 0"
+fi
+cat "${DIAG_TABLE}"
+if [[ -n "${AERO_DIAG_TABLE:-}" ]]; then
+  cat "${AERO_DIAG_TABLE}"
+fi
+cat "${DIAG_TABLE_APPEND}"
+} >> diag_table_template
+
+local template=diag_table_template
+local SYEAR=${current_cycle:0:4}
+local SMONTH=${current_cycle:4:2}
+local SDAY=${current_cycle:6:2}
+local CHOUR=${current_cycle:8:2}
+local MOM6_OUTPUT_DIR="./MOM6_OUTPUT"
+
+atparse < "${template}" >> "diag_table"
+
+
+# copy data table
+${NCP} "${DATA_TABLE}" data_table
+
+# build field_table
+if [[ -n "${AERO_FIELD_TABLE:-}" ]]; then
+  nrec=$(wc -l < "${FIELD_TABLE}")
+  prec=${nrec}
+  if (( dnats > 0 )); then
+    prec=$( grep -F -n TRACER "${FIELD_TABLE}" 2> /dev/null | tail -n "${dnats}" | head -1 | cut -d: -f1 )
+    prec=${prec:-0}
+    prec=$(( prec > 0 ? prec - 1 : prec ))
+  fi
+  { \
+    head -n "${prec}" "${FIELD_TABLE}" ; \
+    cat "${AERO_FIELD_TABLE}" ; \
+    tail -n $(( nrec - prec )) "${FIELD_TABLE}" ; \
+  } > field_table
+  # add non-prognostic tracers from additional table
+  dnats=$(( dnats + dnats_aero ))
+else
+  ${NCP} "${FIELD_TABLE}" field_table
+fi
+fi # only_input_nml
+
+if [[ "${namelist_mode}" == "global" ]] ; then
+    layout_x_here=${layout_x}
+    layout_y_here=${layout_y}
+    ntiles_here=6
+    npx_here=${npx}
+    npy_here=${npy}
+    k_split_here=${k_split}
+else
+    layout_x_here=${layout_x_nest}
+    layout_y_here=${layout_y_nest}
+    ntiles_here=1
+    nested_here=.true.
+    twowaynest_here=${twowaynest:-.true.}
+    nestupdate_here=${nestupdate:-7}
+    npx_here=${npx_nest}
+    npy_here=${npy_nest}
+    k_split_here=${k_split_nest}
+fi
+
+cat > "${nml_file}" <<EOF
+&atmos_model_nml
+  blocksize = ${blocksize}
+  chksum_debug = ${chksum_debug}
+  dycore_only = ${dycore_only}
+  ccpp_suite = ${CCPP_SUITE}
+  ${atmos_model_nml:-}
+/
+
+&diag_manager_nml
+  prepend_date = .false.
+  max_output_fields = 300
+  ${diag_manager_nml:-}
+/
+
+&fms_nml
+  clock_grain = 'ROUTINE'
+  domains_stack_size = ${domains_stack_size:-3000000}
+  print_memory_usage = ${print_memory_usage:-".false."}
+  ${fms_nml:-}
+/
+
+&fms2_io_nml
+  netcdf_default_format = "netcdf4"
+/
+
+&fv_core_nml
+  layout = ${layout_x_here},${layout_y_here}
+  io_layout = ${io_layout}
+  npx = ${npx_here}
+  npy = ${npy_here}
+  ntiles = ${ntiles_here}
+  ${nested_here:+nested = ${nested_here}}
+  ${twowaynest_here:+twowaynest = ${twowaynest_herei}}
+  ${nestupdate_here:+nestupdate = ${nestupdate_here}}
+  npz = ${npz}
+  dz_min =  ${dz_min:-"6"}
+  psm_bc = ${psm_bc:-"0"}
+  grid_type = ${grid_type:-"-1"}
+  make_nh = ${make_nh}
+  fv_debug = ${fv_debug:-".false."}
+  range_warn = ${range_warn:-".true."}
+  reset_eta = .false.
+  n_sponge = ${n_sponge:-"10"}
+  nudge_qv = ${nudge_qv:-".false."}
+  nudge_dz = ${nudge_dz:-".false."}
+  tau = ${tau:-10.}
+  rf_cutoff = ${rf_cutoff:-"7.5e2"}
+  d2_bg_k1 = ${d2_bg_k1:-"0.15"}
+  d2_bg_k2 = ${d2_bg_k2:-"0.02"}
+  kord_tm = ${kord_tm:-"-9"}
+  kord_mt = ${kord_mt:-"9"}
+  kord_wz = ${kord_wz:-"9"}
+  kord_tr = ${kord_tr:-"9"}
+  hydrostatic = ${hydrostatic}
+  phys_hydrostatic = ${phys_hydrostatic}
+  use_hydro_pressure = ${use_hydro_pressure}
+  beta = 0.
+  a_imp = 1.
+  p_fac = 0.1
+  k_split = ${k_split_here}
+  n_split = ${n_split}
+  nwat = ${nwat:-2}
+  na_init = ${na_init}
+  d_ext = 0.
+  dnats = ${dnats}
+  fv_sg_adj = ${fv_sg_adj:-"450"}
+  d2_bg = 0.
+  nord = ${nord:-3}
+  dddmp = ${dddmp:-0.1}
+  d4_bg = ${d4_bg:-0.15}
+  vtdm4 = ${vtdm4}
+  delt_max = ${delt_max:-"0.002"}
+  ke_bg = 0.
+  do_vort_damp = ${do_vort_damp}
+  external_ic = ${external_ic}
+  external_eta = ${external_eta:-.true.}
+  gfs_phil = ${gfs_phil:-".false."}
+  nggps_ic = ${nggps_ic}
+  mountain = ${mountain}
+  ncep_ic = ${ncep_ic}
+  d_con = ${d_con}
+  hord_mt = ${hord_mt}
+  hord_vt = ${hord_xx}
+  hord_tm = ${hord_xx}
+  hord_dp = -${hord_xx}
+  hord_tr = ${hord_tr:-"8"}
+  adjust_dry_mass = ${adjust_dry_mass:-".true."}
+  dry_mass=${dry_mass:-98320.0}
+  consv_te = ${consv_te}
+  do_sat_adj = ${do_sat_adj:-".false."}
+  fast_tau_w_sec = ${fast_tau_w_sec:-"0.2"}
+  consv_am = .false.
+  fill = .true.
+  dwind_2d = .false.
+  print_freq = ${print_freq}
+  warm_start = ${warm_start}
+  no_dycore = ${no_dycore}
+  z_tracer = .true.
+  agrid_vel_rst = ${agrid_vel_rst:-".true."}
+  read_increment = ${read_increment}
+  res_latlon_dynamics = ${res_latlon_dynamics}
+  ${fv_core_nml-}
+EOF
+
+if [[ "${DO_NEST:-NO}" == "YES" && "${namelist_mode}" == "global" ]] ; then
+  cat >> "${nml_file}" <<EOF
+  do_schmidt = .true.
+  target_lat = ${TARGET_LAT}
+  target_lon = ${TARGET_LON}
+  stretch_fac = ${stretch_fac}
+EOF
+fi
+
+if [[ "${DO_NEST:-NO}" == "YES" && "${namelist_mode}" == "nest" ]] ; then
+  cat >> "${nml_file}" <<EOF
+  nested = .true.
+  twowaynest = ${twowaynest:-.true.} ! .true.
+  nestupdate = 7
+EOF
+fi
+
+cat >> "${nml_file}" <<EOF
+/
+
+&external_ic_nml
+  filtered_terrain = ${filtered_terrain}
+  levp = ${LEVS}
+  gfs_dwinds = ${gfs_dwinds}
+  checker_tr = .false.
+  nt_checker = 0
+  ${external_ic_nml-}
+/
+
+&gfs_physics_nml
+  fhzero       = ${FHZER}
+  h2o_phys     = ${h2o_phys:-".true."}
+  ldiag3d      = ${ldiag3d:-".false."}
+  qdiag3d      = ${qdiag3d:-".false."}
+  print_diff_pgr = ${print_diff_pgr:-".false."}
+  fhcyc        = ${FHCYC}
+  use_ufo      = ${use_ufo:-".true."}
+  pre_rad      = ${pre_rad:-".false."}
+  imp_physics  = ${imp_physics:-"99"}
+EOF
+
+case "${CCPP_SUITE:-}" in
+  "FV3_GFS_v15p2_coupled")
+  cat >> "${nml_file}" << EOF
+  oz_phys      = .false.
+  oz_phys_2015 = .true.
+EOF
+  ;;
+  "FV3_GSD_v0")
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+  ltaerosol    = ${ltaerosol:-".false."}
+  lradar       = ${lradar:-".false."}
+  ttendlim     = ${ttendlim:-0.005}
+  oz_phys      = ${oz_phys:-".false."}
+  oz_phys_2015 = ${oz_phys_2015:-".true."}
+  lsoil_lsm    = ${lsoil_lsm:-"4"}
+  do_mynnedmf  = ${do_mynnedmf:-".false."}
+  do_mynnsfclay = ${do_mynnsfclay:-".false."}
+  icloud_bl    = ${icloud_bl:-"1"}
+  bl_mynn_edmf = ${bl_mynn_edmf:-"1"}
+  bl_mynn_tkeadvect=${bl_mynn_tkeadvect:-".true."}
+  bl_mynn_edmf_mom=${bl_mynn_edmf_mom:-"1"}
+  min_lakeice  = ${min_lakeice:-"0.15"}
+  min_seaice   = ${min_seaice:-"0.15"}
+  use_cice_alb = ${use_cice_alb:-".false."}
+EOF
+  ;;
+  FV3_GFS_v16_coupled*)
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+  ltaerosol    = ${ltaerosol:-".false."}
+  lradar       = ${lradar:-".false."}
+  ttendlim     = ${ttendlim:-"0.005"}
+  oz_phys      = ${oz_phys:-".false."}
+  oz_phys_2015 = ${oz_phys_2015:-".true."}
+  do_mynnedmf  = ${do_mynnedmf:-".false."}
+  do_mynnsfclay = ${do_mynnsfclay:-".false."}
+  icloud_bl    = ${icloud_bl:-"1"}
+  bl_mynn_edmf = ${bl_mynn_edmf:-"1"}
+  bl_mynn_tkeadvect = ${bl_mynn_tkeadvect:-".true."}
+  bl_mynn_edmf_mom = ${bl_mynn_edmf_mom:-"1"}
+  min_lakeice  = ${min_lakeice:-"0.15"}
+  min_seaice   = ${min_seaice:-"0.15"}
+EOF
+  ;;
+  FV3_GFS_v16*)
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+  ltaerosol    = ${ltaerosol:-".false."}
+  lradar       = ${lradar:-".false."}
+  ttendlim     = ${ttendlim:-"0.005"}
+  oz_phys      = ${oz_phys:-".false."}
+  oz_phys_2015 = ${oz_phys_2015:-".true."}
+  lsoil_lsm    = ${lsoil_lsm:-"4"}
+  do_mynnedmf  = ${do_mynnedmf:-".false."}
+  do_mynnsfclay = ${do_mynnsfclay:-".false."}
+  icloud_bl    = ${icloud_bl:-"1"}
+  bl_mynn_edmf = ${bl_mynn_edmf:-"1"}
+  bl_mynn_tkeadvect = ${bl_mynn_tkeadvect:-".true."}
+  bl_mynn_edmf_mom = ${bl_mynn_edmf_mom:-"1"}
+  min_lakeice  = ${min_lakeice:-"0.15"}
+  min_seaice   = ${min_seaice:-"0.15"}
+EOF
+  ;;
+  FV3_GFS_v17*)
+  local default_dt_inner=$(( DELTIM/2 ))
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+  ltaerosol    = ${ltaerosol:-".false."}
+  lradar       = ${lradar:-".true."}
+  ttendlim     = ${ttendlim:-"-999"}
+  dt_inner     = ${dt_inner:-"${default_dt_inner}"}
+  sedi_semi    = ${sedi_semi:-".true."}
+  decfl        = ${decfl:-"10"}
+  oz_phys      = ${oz_phys:-".false."}
+  oz_phys_2015 = ${oz_phys_2015:-".true."}
+  lsoil_lsm    = ${lsoil_lsm:-"4"}
+  do_mynnedmf  = ${do_mynnedmf:-".false."}
+  do_mynnsfclay = ${do_mynnsfclay:-".false."}
+  icloud_bl    = ${icloud_bl:-"1"}
+  bl_mynn_edmf = ${bl_mynn_edmf:-"1"}
+  bl_mynn_tkeadvect = ${bl_mynn_tkeadvect:-".true."}
+  bl_mynn_edmf_mom = ${bl_mynn_edmf_mom:-"1"}
+  do_ugwp      = ${do_ugwp:-".false."}
+  do_tofd      = ${do_tofd:-".false."}
+  gwd_opt      = ${gwd_opt:-"2"}
+  do_ugwp_v0   = ${do_ugwp_v0:-".false."}
+  do_ugwp_v1   = ${do_ugwp_v1:-".true."}
+  do_ugwp_v0_orog_only = ${do_ugwp_v0_orog_only:-".false."}
+  do_ugwp_v0_nst_only  = ${do_ugwp_v0_nst_only:-".false."}
+  do_gsl_drag_ls_bl    = ${do_gsl_drag_ls_bl:-".true."}
+  do_gsl_drag_ss       = ${do_gsl_drag_ss:-".true."}
+  do_gsl_drag_tofd     = ${do_gsl_drag_tofd:-".true."}
+  do_ugwp_v1_orog_only = ${do_ugwp_v1_orog_only:-".false."}
+  min_lakeice  = ${min_lakeice:-"0.15"}
+  min_seaice   = ${min_seaice:-"0.15"}
+  use_cice_alb = ${use_cice_alb:-".false."}
+EOF
+  ;;
+  FV3_global_nest*)
+  local default_dt_inner=$(( DELTIM/2 ))
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+  lcnorm       = ${lcnorm:-".false."}
+  ltaerosol    = ${ltaerosol:-".false."}
+  lradar       = ${lradar:-".true."}
+  ttendlim     = ${ttendlim:-"-999"}
+  dt_inner     = ${dt_inner:-"${default_dt_inner}"}
+  sedi_semi    = ${sedi_semi:-".true."}
+  decfl        = ${decfl:-"10"}
+  oz_phys      = ${oz_phys:-".false."}
+  oz_phys_2015 = ${oz_phys_2015:-".true."}
+  lsoil_lsm    = ${lsoil_lsm:-"4"}
+  do_mynnedmf  = ${do_mynnedmf:-".false."}
+  do_mynnsfclay = ${do_mynnsfclay:-".false."}
+  icloud_bl    = ${icloud_bl:-"1"}
+  bl_mynn_edmf = ${bl_mynn_edmf:-"1"}
+  bl_mynn_tkeadvect = ${bl_mynn_tkeadvect:-".true."}
+  bl_mynn_edmf_mom = ${bl_mynn_edmf_mom:-"1"}
+  do_ugwp      = ${do_ugwp:-".false."}
+  do_tofd      = ${do_tofd:-".false."}
+  gwd_opt      = ${gwd_opt:-"2"}
+  do_ugwp_v0   = ${do_ugwp_v0:-".false."}
+  do_ugwp_v1   = ${do_ugwp_v1:-".true."}
+  do_ugwp_v0_orog_only = ${do_ugwp_v0_orog_only:-".false."}
+  do_ugwp_v0_nst_only  = ${do_ugwp_v0_nst_only:-".false."}
+  do_gsl_drag_ls_bl    = ${do_gsl_drag_ls_bl:-".true."}
+  do_gsl_drag_ss       = ${do_gsl_drag_ss:-".true."}
+  do_gsl_drag_tofd     = ${do_gsl_drag_tofd:-".true."}
+  do_ugwp_v1_orog_only = ${do_ugwp_v1_orog_only:-".false."}
+  min_lakeice  = ${min_lakeice:-"0.15"}
+  min_seaice   = ${min_seaice:-"0.15"}
+  use_cice_alb = ${use_cice_alb:-".false."}
+EOF
+  ;;
+  *)
+  cat >> "${nml_file}" << EOF
+  iovr         = ${iovr:-"3"}
+EOF
+  ;;
+esac
+
+cat >> "${nml_file}" <<EOF
+  pdfcld       = ${pdfcld:-".false."}
+  fhswr        = ${FHSWR:-"3600."}
+  fhlwr        = ${FHLWR:-"3600."}
+  ialb         = ${IALB:-"1"}
+  iems         = ${IEMS:-"1"}
+  iaer         = ${IAER}
+  icliq_sw     = ${icliq_sw:-"2"}
+  ico2         = ${ICO2}
+  isubc_sw     = ${isubc_sw:-"2"}
+  isubc_lw     = ${isubc_lw:-"2"}
+  isol         = ${ISOL:-"2"}
+  lwhtr        = ${lwhtr:-".true."}
+  swhtr        = ${swhtr:-".true."}
+  cnvgwd       = ${cnvgwd:-".true."}
+  shal_cnv     = ${shal_cnv:-".true."}
+  cal_pre      = ${cal_pre:-".true."}
+  redrag       = ${redrag:-".true."}
+  dspheat      = ${dspheat:-".true."}
+  hybedmf      = ${hybedmf:-".false."}
+  satmedmf     = ${satmedmf-".true."}
+  isatmedmf    = ${isatmedmf-"1"}
+  lheatstrg    = ${lheatstrg-".false."}
+  lseaspray    = ${lseaspray:-".true."}
+  random_clds  = ${random_clds:-".true."}
+  trans_trac   = ${trans_trac:-".true."}
+  cnvcld       = ${cnvcld:-".true."}
+  imfshalcnv   = ${imfshalcnv:-"2"}
+  imfdeepcnv   = ${imfdeepcnv:-"2"}
+  progsigma    = ${progsigma:-".true."}
+  betascu      = ${betascu:-"8.0"}
+  betamcu      = ${betamcu:-"1.0"}
+  betadcu      = ${betadcu:-"2.0"}
+  ras          = ${ras:-".false."}
+  cdmbgwd      = ${cdmbgwd:-"3.5,0.25"}
+  prslrd0      = ${prslrd0:-"0."}
+  ivegsrc      = ${ivegsrc:-"1"}
+  isot         = ${isot:-"1"}
+  lsoil        = ${lsoil:-"4"}
+  lsm          = ${lsm:-"2"}
+  iopt_dveg    = ${iopt_dveg:-"1"}
+  iopt_crs     = ${iopt_crs:-"1"}
+  iopt_btr     = ${iopt_btr:-"1"}
+  iopt_run     = ${iopt_run:-"1"}
+  iopt_sfc     = ${iopt_sfc:-"1"}
+  iopt_frz     = ${iopt_frz:-"1"}
+  iopt_inf     = ${iopt_inf:-"1"}
+  iopt_rad     = ${iopt_rad:-"1"}
+  iopt_alb     = ${iopt_alb:-"2"}
+  iopt_snf     = ${iopt_snf:-"4"}
+  iopt_tbot    = ${iopt_tbot:-"2"}
+  iopt_stc     = ${iopt_stc:-"1"}
+  iopt_trs     = ${iopt_trs:-"2"}
+  iopt_diag    = ${iopt_diag:-"1"}
+  debug        = ${gfs_phys_debug:-".false."}
+  nstf_name    = ${nstf_name}
+  nst_anl      = ${nst_anl}
+  psautco      = ${psautco:-"0.0008,0.0005"}
+  prautco      = ${prautco:-"0.00015,0.00015"}
+  lgfdlmprad   = ${lgfdlmprad:-".false."}
+  effr_in      = ${effr_in:-".false."}
+  ldiag_ugwp   = ${ldiag_ugwp:-".false."}
+  do_RRTMGP          = ${do_RRTMGP:-".false."}
+  active_gases       = ${active_gases:-'h2o_co2_o3_n2o_ch4_o2'}
+  ngases             = ${ngases:-"6"}
+  lw_file_gas        = ${lw_file_gas:-'rrtmgp-data-lw-g128-210809.nc'}
+  lw_file_clouds     = ${lw_file_clouds:-'rrtmgp-cloud-optics-coeffs-lw.nc'}
+  sw_file_gas        = ${sw_file_gas:-'rrtmgp-data-sw-g112-210809.nc'}
+  sw_file_clouds     = ${sw_file_clouds:-'rrtmgp-cloud-optics-coeffs-sw.nc'}
+  rrtmgp_nGptsSW     = ${rrtmgp_nGptsSW:-"112"}
+  rrtmgp_nGptsLW     = ${rrtmgp_nGptsLW:-"128"}
+  rrtmgp_nBandsLW    = ${rrtmgp_nBandsLW:-"16"}
+  rrtmgp_nBandsSW    = ${rrtmgp_nBandsSW:-"14"}
+  doGP_cldoptics_LUT = ${doGP_cldoptics_LUT:-".false."}
+  doGP_lwscat        = ${doGP_lwscat:-".false."}
+EOF
+
+if [[ ${cplchm} = ".true." ]]; then
+  cat >> "${nml_file}" << EOF
+  fscav_aero = ${fscav_aero:-'*:0.0'}
+EOF
+fi
+
+cat >> "${nml_file}" <<EOF
+  do_sppt      = ${do_sppt:-".false."}
+  do_shum      = ${do_shum:-".false."}
+  do_skeb      = ${do_skeb:-".false."}
+  frac_grid    = ${FRAC_GRID:-".true."}
+  cplchm       = ${cplchm:-".false."}
+  cplflx       = ${cplflx:-".false."}
+  cplice       = ${cplice:-".false."}
+  cplwav       = ${cplwav:-".false."}
+  cplwav2atm   = ${cplwav2atm:-".false."}
+EOF
+
+if [[ ${DO_SPPT} = "YES" ]]; then
+cat >> "${nml_file}" <<EOF
+  pert_mp = .false.
+  pert_radtend = .false.
+  pert_clds = .true.
+EOF
+fi
+
+# Add namelist for IAU
+if [[ ${DOIAU} = "YES" ]]; then
+  cat >> "${nml_file}" << EOF
+  iaufhrs      = ${IAUFHRS}
+  iau_delthrs  = ${IAU_DELTHRS}
+  iau_inc_files= ${IAU_INC_FILES}
+  iau_drymassfixer = .false.
+  iau_filter_increments = ${IAU_FILTER_INCREMENTS:-".false."}
+EOF
+fi
+
+if [[ ${DO_CA:-"NO"} = "YES" ]]; then
+  cat >> "${nml_file}" << EOF
+  do_ca      = .true.
+  ca_global  = ${ca_global:-".false."}
+  ca_sgs     = ${ca_sgs:-".true."}
+  nca        = ${nca:-"1"}
+  ncells     = ${ncells:-"5"}
+  nlives     = ${nlives:-"12"}
+  nseed      = ${nseed:-"1"}
+  nfracseed  = ${nfracseed:-"0.5"}
+  nthresh    = ${nthresh:-"18"}
+  ca_trigger = ${ca_trigger:-".true."}
+  nspinup    = ${nspinup:-"1"}
+  iseed_ca   = ${ISEED_CA:-"12345"}
+EOF
+fi
+
+if [[ "${DO_LAND_PERT:-NO}" == "YES" ]]; then
+  cat >> "${nml_file}" << EOF
+  lndp_type = ${lndp_type:-2}
+  n_var_lndp = ${n_var_lndp:-0}
+EOF
+fi
+
+# Close &gfs_physics_nml section
+cat >> "${nml_file}" << EOF
+/
+EOF
+
+if [[ "${namelist_mode}" == "global" ]] ; then
+  cat >> "${nml_file}" << EOF
+&fv_nest_nml
+  grid_pes = $(( layout_x * layout_y * 6 )),$(( layout_x_nest * layout_y_nest ))
+  tile_coarse = 0,6
+  num_tile_top = 6
+  p_split = 1
+  nest_refine = 0,${nest_refine}
+  nest_ioffsets = 0,${nest_ioffset}
+  nest_joffsets = 0,${nest_joffset}
+/
+EOF
+fi
+
+if [[ ${knob_ugwp_version} -eq 0 ]]; then
+  cat >> "${nml_file}" << EOF
+&cires_ugwp_nml
+  knob_ugwp_solver  = ${knob_ugwp_solver:-2}
+  knob_ugwp_source  = ${knob_ugwp_source:-1,1,0,0}
+  knob_ugwp_wvspec  = ${knob_ugwp_wvspec:-1,25,25,25}
+  knob_ugwp_azdir   = ${knob_ugwp_azdir:-2,4,4,4}
+  knob_ugwp_stoch   = ${knob_ugwp_stoch:-0,0,0,0}
+  knob_ugwp_effac   = ${knob_ugwp_effac:-1,1,1,1}
+  knob_ugwp_doaxyz  = ${knob_ugwp_doaxyz:-1}
+  knob_ugwp_doheat  = ${knob_ugwp_doheat:-1}
+  knob_ugwp_dokdis  = ${knob_ugwp_dokdis:-1}
+  knob_ugwp_ndx4lh  = ${knob_ugwp_ndx4lh:-1}
+  knob_ugwp_version = ${knob_ugwp_version:-0}
+  launch_level      = ${launch_level:-54}
+/
+EOF
+fi
+
+if [[ ${knob_ugwp_version} -eq 1 ]]; then
+  cat >> "${nml_file}" << EOF
+&cires_ugwp_nml
+  knob_ugwp_solver  = ${knob_ugwp_solver:-2}
+  knob_ugwp_source  = ${knob_ugwp_source:-1,1,0,0}
+  knob_ugwp_wvspec  = ${knob_ugwp_wvspec:-1,25,25,25}
+  knob_ugwp_azdir   = ${knob_ugwp_azdir:-2,4,4,4}
+  knob_ugwp_stoch   = ${knob_ugwp_stoch:-0,0,0,0}
+  knob_ugwp_effac   = ${knob_ugwp_effac:-1,1,1,1}
+  knob_ugwp_doaxyz  = ${knob_ugwp_doaxyz:-1}
+  knob_ugwp_doheat  = ${knob_ugwp_doheat:-1}
+  knob_ugwp_dokdis  = ${knob_ugwp_dokdis:-2}
+  knob_ugwp_ndx4lh  = ${knob_ugwp_ndx4lh:-4}
+  knob_ugwp_version = ${knob_ugwp_version:-1}
+  knob_ugwp_palaunch = ${knob_ugwp_palaunch:-275.0e2}
+  knob_ugwp_nslope   = ${knob_ugwp_nslope:-1}
+  knob_ugwp_lzmax    = ${knob_ugwp_lzmax:-15.750e3}
+  knob_ugwp_lzmin    = ${knob_ugwp_lzmin:-0.75e3}
+  knob_ugwp_lzstar   = ${knob_ugwp_lzstar:-2.0e3}
+  knob_ugwp_taumin   = ${knob_ugwp_taumin:-0.25e-3}
+  knob_ugwp_tauamp   = ${knob_ugwp_tauamp:-3.0e-3}
+  knob_ugwp_lhmet    = ${knob_ugwp_lhmet:-200.0e3}
+  knob_ugwp_orosolv  = ${knob_ugwp_orosolv:-'pss-1986'}
+/
+EOF
+fi
+
+echo "" >> "${nml_file}"
+
+cat >> "${nml_file}" <<EOF
+&gfdl_cloud_microphysics_nml
+  sedi_transport = .true.
+  do_sedi_heat = .false.
+  rad_snow = .true.
+  rad_graupel = .true.
+  rad_rain = .true.
+  const_vi = .false.
+  const_vs = .false.
+  const_vg = .false.
+  const_vr = .false.
+  vi_max = 1.
+  vs_max = 2.
+  vg_max = 12.
+  vr_max = 12.
+  qi_lim = 1.
+  prog_ccn = .false.
+  do_qa = .true.
+  fast_sat_adj = .true.
+  tau_l2v = 225.
+  tau_v2l = 150.
+  tau_g2v = 900.
+  rthresh = 10.e-6  ! This is a key parameter for cloud water
+  dw_land  = 0.16
+  dw_ocean = 0.10
+  ql_gen = 1.0e-3
+  ql_mlt = 1.0e-3
+  qi0_crt = 8.0E-5
+  qs0_crt = 1.0e-3
+  tau_i2s = 1000.
+  c_psaci = 0.05
+  c_pgacs = 0.01
+  rh_inc = 0.30
+  rh_inr = 0.30
+  rh_ins = 0.30
+  ccn_l = 300.
+  ccn_o = 100.
+  c_paut = 0.5
+  c_cracw = 0.8
+  use_ppm = .false.
+  use_ccn = .true.
+  mono_prof = .true.
+  z_slope_liq  = .true.
+  z_slope_ice  = .true.
+  de_ice = .false.
+  fix_negative = .true.
+  icloud_f = 1
+  mp_time = 150.
+  reiflag = ${reiflag:-"2"}
+
+  ${gfdl_cloud_microphysics_nml:-}
+/
+
+&interpolator_nml
+  interp_method = 'conserve_great_circle'
+  ${interpolator_nml:-}
+/
+
+&namsfc
+  FNGLAC   = '${FNGLAC}'
+  FNMXIC   = '${FNMXIC}'
+  FNTSFC   = '${FNTSFC}'
+  FNSNOC   = '${FNSNOC}'
+  FNZORC   = '${FNZORC}'
+  FNALBC   = '${FNALBC}'
+  FNALBC2  = '${FNALBC2}'
+  FNAISC   = '${FNAISC}'
+  FNTG3C   = '${FNTG3C}'
+  FNVEGC   = '${FNVEGC}'
+  FNVETC   = '${FNVETC}'
+  FNSOTC   = '${FNSOTC}'
+  FNSOCC   = '${FNSOCC}'
+  FNSMCC   = '${FNSMCC}'
+  FNMSKH   = '${FNMSKH}'
+  FNTSFA   = '${FNTSFA}'
+  FNACNA   = '${FNACNA:-}'
+  FNSNOA   = '${FNSNOA:-}'
+  FNVMNC   = '${FNVMNC:-}'
+  FNVMXC   = '${FNVMXC:-}'
+  FNSLPC   = '${FNSLPC:-}'
+  FNABSC   = '${FNABSC:-}'
+  LDEBUG = ${LDEBUG:-".false."}
+  FSMCL(2) = ${FSMCL2:-99999}
+  FSMCL(3) = ${FSMCL3:-99999}
+  FSMCL(4) = ${FSMCL4:-99999}
+  LANDICE  = ${landice:-".true."}
+  FTSFS = ${FTSFS:-90}
+  FAISL = ${FAISL:-99999}
+  FAISS = ${FAISS:-99999}
+  FSNOL = ${FSNOL:-99999}
+  FSNOS = ${FSNOS:-99999}
+  FSICL = ${FSICL:-99999}
+  FSICS = ${FSICS:-99999}
+  FTSFL = ${FTSFL:-99999}
+  FVETL = ${FVETL:-99999}
+  FSOTL = ${FSOTL:-99999}
+  FvmnL = ${FvmnL:-99999}
+  FvmxL = ${FvmxL:-99999}
+  FSLPL = ${FSLPL:-99999}
+  FABSL = ${FABSL:-99999}
+  ${namsfc_nml:-}
+/
+
+&fv_grid_nml
+EOF
+if [[ "${DO_NEST:-NO}" == "NO" ]] ; then
+    cat >> "${nml_file}" <<EOF
+  grid_file = 'INPUT/grid_spec.nc'
+EOF
+fi
+
+cat >> "${nml_file}" <<EOF
+  ${fv_grid_nml:-}
+/
+EOF
+
+# Add namelist for stochastic physics options
+echo "" >> "${nml_file}"
+#if [ $MEMBER -gt 0 ]; then
+if [[ "${DO_SPPT}" = "YES" || "${DO_SHUM}" = "YES" || "${DO_SKEB}" = "YES" || "${DO_LAND_PERT}" = "YES" ]]; then
+
+    cat >> "${nml_file}" << EOF
+&nam_stochy
+EOF
+
+  if [[ ${DO_SKEB} = "YES" ]]; then
+    cat >> "${nml_file}" << EOF
+  skeb = ${SKEB}
+  iseed_skeb = ${ISEED_SKEB:-${ISEED}}
+  skeb_tau = ${SKEB_TAU:-"-999."}
+  skeb_lscale = ${SKEB_LSCALE:-"-999."}
+  skebnorm = ${SKEBNORM:-"1"}
+  skeb_npass = ${SKEB_NPASS:-"30"}
+  skeb_vdof = ${SKEB_VDOF:-"5"}
+EOF
+  fi
+
+  if [[ ${DO_SHUM} = "YES" ]]; then
+    cat >> "${nml_file}" << EOF
+  shum = ${SHUM}
+  iseed_shum = ${ISEED_SHUM:-${ISEED}}
+  shum_tau = ${SHUM_TAU:-"-999."}
+  shum_lscale = ${SHUM_LSCALE:-"-999."}
+EOF
+  fi
+
+  if [[ ${DO_SPPT} = "YES" ]]; then
+    cat >> "${nml_file}" << EOF
+  sppt = ${SPPT}
+  iseed_sppt = ${ISEED_SPPT:-${ISEED}}
+  sppt_tau = ${SPPT_TAU:-"-999."}
+  sppt_lscale = ${SPPT_LSCALE:-"-999."}
+  sppt_logit = ${SPPT_LOGIT:-".true."}
+  sppt_sfclimit = ${SPPT_SFCLIMIT:-".true."}
+  use_zmtnblck = ${use_zmtnblck:-".true."}
+  pbl_taper = ${pbl_taper:-"0,0,0,0.125,0.25,0.5,0.75"}
+EOF
+  fi
+
+  if [[ "${DO_OCN_SPPT:-NO}" == "YES" ]]; then
+    cat >> "${nml_file}" <<EOF
+  OCNSPPT=${OCNSPPT}
+  OCNSPPT_LSCALE=${OCNSPPT_LSCALE}
+  OCNSPPT_TAU=${OCNSPPT_TAU}
+  ISEED_OCNSPPT=${ISEED_OCNSPPT:-${ISEED}}
+EOF
+  fi
+
+  if [[ "${DO_OCN_PERT_EPBL:-NO}" == "YES" ]]; then
+    cat >> "${nml_file}" <<EOF
+  EPBL=${EPBL}
+  EPBL_LSCALE=${EPBL_LSCALE}
+  EPBL_TAU=${EPBL_TAU}
+  ISEED_EPBL=${ISEED_EPBL:-${ISEED}}
+EOF
+  fi
+
+  if [[ "${DO_OCN_SPPT:-NO}" == "YES" ]]; then
+    cat >> "${nml_file}" <<EOF
+  OCNSPPT=${OCNSPPT}
+  OCNSPPT_LSCALE=${OCNSPPT_LSCALE}
+  OCNSPPT_TAU=${OCNSPPT_TAU}
+  ISEED_OCNSPPT=${ISEED_OCNSPPT:-${ISEED}}
+EOF
+  fi
+
+  if [[ "${DO_OCN_PERT_EPBL:-NO}" == "YES" ]]; then
+    cat >> "${nml_file}" <<EOF
+  EPBL=${EPBL}
+  EPBL_LSCALE=${EPBL_LSCALE}
+  EPBL_TAU=${EPBL_TAU}
+  ISEED_EPBL=${ISEED_EPBL:-${ISEED}}
+EOF
+  fi
+
+  cat >> "${nml_file}" << EOF
+/
+EOF
+
+  if [[ ${DO_LAND_PERT} = "YES" ]]; then
+    cat >> "${nml_file}" << EOF
+&nam_sfcperts
+  lndp_type = ${lndp_type}
+  LNDP_TAU = ${LNDP_TAU}
+  LNDP_SCALE = ${LNDP_SCALE}
+  ISEED_LNDP = ${ISEED_LNDP:-${ISEED}}
+  lndp_var_list = ${lndp_var_list}
+  lndp_prt_list = ${lndp_prt_list}
+/
+EOF
+  else
+    cat >> "${nml_file}" << EOF
+&nam_sfcperts
+/
+EOF
+  fi
+
+else
+
+  cat >> "${nml_file}" << EOF
+&nam_stochy
+/
+&nam_sfcperts
+/
+EOF
+
+fi
+
+# Echo out formatted ""${nml_file}""
+echo "===================================="
+echo "FV3_namelists_nest(): '${nml_file}'"
+cat "${nml_file}"
+echo "===================================="
+}
diff --git a/ush/python/pygfs/task/analysis.py b/ush/python/pygfs/task/analysis.py
index 078e013e7f..02011423b7 100644
--- a/ush/python/pygfs/task/analysis.py
+++ b/ush/python/pygfs/task/analysis.py
@@ -25,7 +25,6 @@ class Analysis(Task):
 
     def __init__(self, config: Dict[str, Any]) -> None:
         super().__init__(config)
-        self.config.ntiles = 6
         # Store location of GDASApp jinja2 templates
         self.gdasapp_j2tmpl_dir = os.path.join(self.config.PARMgfs, 'gdas')