diff --git a/.gitmodules b/.gitmodules
index a3775fc12d..1a958b9109 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,7 +1,9 @@
 [submodule "FV3"]
   path = FV3
-  url = https://github.com/NOAA-EMC/fv3atm
-  branch = develop
+#  url = https://github.com/NOAA-EMC/fv3atm
+#  branch = develop
+  url = https://github.com/DavidNew-NOAA/fv3atm
+  branch = feature/cubed_sphere_inc
 [submodule "WW3"]
   path = WW3
   url = https://github.com/NOAA-EMC/WW3
diff --git a/FV3 b/FV3
index 66bded5b3e..40fa2b517f 160000
--- a/FV3
+++ b/FV3
@@ -1 +1 @@
-Subproject commit 66bded5b3e6fefc181f7df433acd18c392267311
+Subproject commit 40fa2b517f4502728d37c85ebfd2d8762fb40a4a
diff --git a/tests/default_vars.sh b/tests/default_vars.sh
index 78a89ec8e6..b7beeef5bb 100644
--- a/tests/default_vars.sh
+++ b/tests/default_vars.sh
@@ -555,6 +555,7 @@ export MODEL_INITIALIZATION=false
 export WARM_START=.false.
 export READ_INCREMENT=.false.
 export RES_LATLON_DYNAMICS="''"
+export INCREMENT_FILE_ON_NATIVE_GRID=.false.
 export NGGPS_IC=.true.
 export EXTERNAL_IC=.true.
 export MAKE_NH=.true.
diff --git a/tests/parm/control.nml.IN b/tests/parm/control.nml.IN
index d48d1fb422..c7b45874f1 100644
--- a/tests/parm/control.nml.IN
+++ b/tests/parm/control.nml.IN
@@ -89,6 +89,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/control_ca.nml.IN b/tests/parm/control_ca.nml.IN
index 95abe17265..527eb7e296 100644
--- a/tests/parm/control_ca.nml.IN
+++ b/tests/parm/control_ca.nml.IN
@@ -89,6 +89,7 @@
   agrid_vel_rst = .true.
   read_increment = .false.
   res_latlon_dynamics = ""
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/control_csawmg.nml.IN b/tests/parm/control_csawmg.nml.IN
index 6729ed1031..88a46c3e58 100644
--- a/tests/parm/control_csawmg.nml.IN
+++ b/tests/parm/control_csawmg.nml.IN
@@ -87,6 +87,7 @@
   z_tracer = .true.
   agrid_vel_rst = .true.
   read_increment = .false.
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
   res_latlon_dynamics = ""
 /
 
diff --git a/tests/parm/control_flake.nml.IN b/tests/parm/control_flake.nml.IN
index cea5817471..27f96e5c61 100644
--- a/tests/parm/control_flake.nml.IN
+++ b/tests/parm/control_flake.nml.IN
@@ -88,6 +88,7 @@
   agrid_vel_rst = .true.
   read_increment = .false.
   res_latlon_dynamics = ""
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/control_gdas.nml.IN b/tests/parm/control_gdas.nml.IN
index 9ffeadd0e3..0d5991b24a 100644
--- a/tests/parm/control_gdas.nml.IN
+++ b/tests/parm/control_gdas.nml.IN
@@ -91,7 +91,7 @@
   agrid_vel_rst = .true.
   read_increment = .false.
   res_latlon_dynamics = ""
-
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &cires_ugwp_nml
diff --git a/tests/parm/control_gfsv17.nml.IN b/tests/parm/control_gfsv17.nml.IN
index 247cca85e8..ce77835c8f 100644
--- a/tests/parm/control_gfsv17.nml.IN
+++ b/tests/parm/control_gfsv17.nml.IN
@@ -89,6 +89,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/control_noahmp.nml.IN b/tests/parm/control_noahmp.nml.IN
index 6082aa789b..bc61672a00 100644
--- a/tests/parm/control_noahmp.nml.IN
+++ b/tests/parm/control_noahmp.nml.IN
@@ -88,6 +88,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/csawmg3shoc127.nml.IN b/tests/parm/csawmg3shoc127.nml.IN
index b01ba5f205..d510d0ca6f 100644
--- a/tests/parm/csawmg3shoc127.nml.IN
+++ b/tests/parm/csawmg3shoc127.nml.IN
@@ -90,6 +90,7 @@
        z_tracer   = .true.
        read_increment = @[READ_INCREMENT]
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/csawmgshoc.nml.IN b/tests/parm/csawmgshoc.nml.IN
index 3f77e6fd0f..2bd6144f3e 100644
--- a/tests/parm/csawmgshoc.nml.IN
+++ b/tests/parm/csawmgshoc.nml.IN
@@ -89,6 +89,7 @@
        z_tracer   = .true.
        read_increment = @[READ_INCREMENT]
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/global_control.nml.IN b/tests/parm/global_control.nml.IN
index ecdc0c5d0b..8868906af9 100644
--- a/tests/parm/global_control.nml.IN
+++ b/tests/parm/global_control.nml.IN
@@ -94,6 +94,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/input_global_hafs.nml.IN b/tests/parm/input_global_hafs.nml.IN
index fdc887c8f5..2c7173fce7 100644
--- a/tests/parm/input_global_hafs.nml.IN
+++ b/tests/parm/input_global_hafs.nml.IN
@@ -94,6 +94,7 @@
        agrid_vel_rst = .true.
        read_increment = .false.
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
        write_3d_diags = .true.
 
        do_schmidt = .true.
diff --git a/tests/parm/input_global_nest.nml.IN b/tests/parm/input_global_nest.nml.IN
index affbb2af94..dab50280d1 100644
--- a/tests/parm/input_global_nest.nml.IN
+++ b/tests/parm/input_global_nest.nml.IN
@@ -101,6 +101,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
   nested = @[NESTED]
   twowaynest = @[TWOWAYNEST02]
   nestupdate = 7
diff --git a/tests/parm/input_global_parent.nml.IN b/tests/parm/input_global_parent.nml.IN
index 2027367087..33c1baa34f 100644
--- a/tests/parm/input_global_parent.nml.IN
+++ b/tests/parm/input_global_parent.nml.IN
@@ -100,6 +100,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
   do_schmidt = .true.
   target_lat = @[TARGET_LAT]
   target_lon = @[TARGET_LON]
diff --git a/tests/parm/input_nest02.nml.IN b/tests/parm/input_nest02.nml.IN
index 561afaffa9..4056f629bb 100644
--- a/tests/parm/input_nest02.nml.IN
+++ b/tests/parm/input_nest02.nml.IN
@@ -89,6 +89,7 @@
        warm_start = @[WARM_START]
        read_increment = @[READ_INCREMENT]
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
        no_dycore = .false.
        z_tracer = .true.
 
diff --git a/tests/parm/input_nest_hafs.nml.IN b/tests/parm/input_nest_hafs.nml.IN
index 3fdf8e7d5e..055e4ddeac 100644
--- a/tests/parm/input_nest_hafs.nml.IN
+++ b/tests/parm/input_nest_hafs.nml.IN
@@ -94,6 +94,7 @@
        agrid_vel_rst = .true.
        read_increment = .false.
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
        write_3d_diags = .true.
 
        nested = .true.
diff --git a/tests/parm/input_regional_hafs.nml.IN b/tests/parm/input_regional_hafs.nml.IN
index d88db070ef..95cec669bd 100644
--- a/tests/parm/input_regional_hafs.nml.IN
+++ b/tests/parm/input_regional_hafs.nml.IN
@@ -93,6 +93,7 @@
        agrid_vel_rst = .true.
        read_increment = .false.
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
        write_3d_diags = .true.
 
        do_schmidt = .true.
diff --git a/tests/parm/rap.nml.IN b/tests/parm/rap.nml.IN
index 8ed7dcfa75..849e9f78cc 100644
--- a/tests/parm/rap.nml.IN
+++ b/tests/parm/rap.nml.IN
@@ -90,6 +90,7 @@
   agrid_vel_rst = .true.
   read_increment = @[READ_INCREMENT]
   res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+  increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml
diff --git a/tests/parm/regional.nml.IN b/tests/parm/regional.nml.IN
index 511cbe1e34..f0911503c7 100644
--- a/tests/parm/regional.nml.IN
+++ b/tests/parm/regional.nml.IN
@@ -96,6 +96,7 @@
        agrid_vel_rst = .true.
        read_increment = .F.
        res_latlon_dynamics = "fv3_increment.nc"
+       increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
        do_schmidt = .true.
        target_lat = 55.0
        target_lon = -112.5
diff --git a/tests/parm/regional_atmaq.nml.IN b/tests/parm/regional_atmaq.nml.IN
index 0a5b3e3812..a5a596a55c 100644
--- a/tests/parm/regional_atmaq.nml.IN
+++ b/tests/parm/regional_atmaq.nml.IN
@@ -93,6 +93,7 @@
     regional = .true.
     regional_bcs_from_gsi = .false.
     res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+    increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
     reset_eta = .false.
     rf_cutoff = 750.0
     stretch_fac = 0.999
diff --git a/tests/parm/regional_rrfs_a.nml.IN b/tests/parm/regional_rrfs_a.nml.IN
index 1e1255e81b..d7c903a954 100644
--- a/tests/parm/regional_rrfs_a.nml.IN
+++ b/tests/parm/regional_rrfs_a.nml.IN
@@ -120,6 +120,7 @@
     regional = .true.
     regional_bcs_from_gsi = .false.
     res_latlon_dynamics = 'fv3_increment.nc'
+    increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
     reset_eta = .false.
     rf_cutoff = 2000.0
     sg_cutoff = 10000.0
diff --git a/tests/parm/regional_wofs.nml.IN b/tests/parm/regional_wofs.nml.IN
index e79f196863..e5d49e3858 100644
--- a/tests/parm/regional_wofs.nml.IN
+++ b/tests/parm/regional_wofs.nml.IN
@@ -112,6 +112,7 @@
     regional = .true.
     regional_bcs_from_gsi = .false.
     res_latlon_dynamics = 'fv3_increment.nc'
+    increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
     reset_eta = .false.
     rf_cutoff = 2000.0
     stretch_fac = 0.999
diff --git a/tests/parm/rrfs_conus13km_hrrr.nml.IN b/tests/parm/rrfs_conus13km_hrrr.nml.IN
index 883a508911..b582d1d357 100644
--- a/tests/parm/rrfs_conus13km_hrrr.nml.IN
+++ b/tests/parm/rrfs_conus13km_hrrr.nml.IN
@@ -115,6 +115,7 @@
     regional = .true.
     regional_bcs_from_gsi = .false.
     res_latlon_dynamics = @[RES_LATLON_DYNAMICS]
+    increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
     reset_eta = .false.
     rf_cutoff = 20000.0
     sg_cutoff = 10000.0
diff --git a/tests/parm/wam_v17.nml.IN b/tests/parm/wam_v17.nml.IN
index 8e5c6cb90d..f6ec526bc7 100644
--- a/tests/parm/wam_v17.nml.IN
+++ b/tests/parm/wam_v17.nml.IN
@@ -93,6 +93,7 @@
     agrid_vel_rst = .false.
     read_increment = @[READ_INCREMENT]
     res_latlon_dynamics = "fv3_increment.nc"
+    increment_file_on_native_grid = @[INCREMENT_FILE_ON_NATIVE_GRID]
 /
 
 &external_ic_nml