diff --git a/dev/ci/cases/gcafsv1/C384_gcafs_cycled.yaml b/dev/ci/cases/gcafsv1/C384_gcafs_cycled.yaml
index 2a2677fa08d..587a40b7382 100644
--- a/dev/ci/cases/gcafsv1/C384_gcafs_cycled.yaml
+++ b/dev/ci/cases/gcafsv1/C384_gcafs_cycled.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 384
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250327
+  icsdir: {{ BASE_IC }}/C96C48/20250327
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA.yaml b/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA.yaml
index ecb8ec678f1..58519b3e583 100644
--- a/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA.yaml
+++ b/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 384
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250327
+  icsdir: {{ BASE_IC }}/C96C48/20250327
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA_dev.yaml b/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA_dev.yaml
index 773258b85fb..e3e27c27003 100644
--- a/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA_dev.yaml
+++ b/dev/ci/cases/gcafsv1/C384_gcafs_cycled_noDA_dev.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 384
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250327
+  icsdir: {{ BASE_IC }}/C96C48/20250327
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/gcafsv1/C96_gcafs_cycled.yaml b/dev/ci/cases/gcafsv1/C96_gcafs_cycled.yaml
index 937c1263397..9781f4af06b 100644
--- a/dev/ci/cases/gcafsv1/C96_gcafs_cycled.yaml
+++ b/dev/ci/cases/gcafsv1/C96_gcafs_cycled.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA.yaml b/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA.yaml
index 1e70b22bc75..10c7a64f120 100644
--- a/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA.yaml
+++ b/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA_dev.yaml b/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA_dev.yaml
index 20fde3e50c1..ec147924fd2 100644
--- a/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA_dev.yaml
+++ b/dev/ci/cases/gcafsv1/C96_gcafs_cycled_noDA_dev.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122200
   nens: 0
diff --git a/dev/ci/cases/pr/C48_gsienkf_atmDA.yaml b/dev/ci/cases/pr/C48_gsienkf_atmDA.yaml
index fd1f2d12ac2..931e9ea8626 100644
--- a/dev/ci/cases/pr/C48_gsienkf_atmDA.yaml
+++ b/dev/ci/cases/pr/C48_gsienkf_atmDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2024022318
   edate: 2024022406
   nens: 2
diff --git a/dev/ci/cases/pr/C48_ufsenkf_atmDA.yaml b/dev/ci/cases/pr/C48_ufsenkf_atmDA.yaml
index 2067ccbb956..2e81a2fd3d1 100644
--- a/dev/ci/cases/pr/C48_ufsenkf_atmDA.yaml
+++ b/dev/ci/cases/pr/C48_ufsenkf_atmDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2024022318
   edate: 2024022406
   nens: 2
diff --git a/dev/ci/cases/pr/C48mx500_3DVarAOWCDA.yaml b/dev/ci/cases/pr/C48mx500_3DVarAOWCDA.yaml
index c6788b9d532..1be12e2977b 100644
--- a/dev/ci/cases/pr/C48mx500_3DVarAOWCDA.yaml
+++ b/dev/ci/cases/pr/C48mx500_3DVarAOWCDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resdetocean: 5.0
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C48mx500/20250808
+  icsdir: {{ BASE_IC }}/C48mx500/20250808
   idate: 2021032418
   edate: 2021032500
   nens: 0
diff --git a/dev/ci/cases/pr/C48mx500_hybAOWCDA.yaml b/dev/ci/cases/pr/C48mx500_hybAOWCDA.yaml
index d1fa21c367e..37af0db1c4d 100644
--- a/dev/ci/cases/pr/C48mx500_hybAOWCDA.yaml
+++ b/dev/ci/cases/pr/C48mx500_hybAOWCDA.yaml
@@ -8,7 +8,7 @@ experiment:
   resdetocean: 5.0
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C48mx500/20250808
+  icsdir: {{ BASE_IC }}/C48mx500/20250808
   idate: 2021032418
   edate: 2021032500
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48_hybatmDA.yaml b/dev/ci/cases/pr/C96C48_hybatmDA.yaml
index cbfc8c70763..c85e68e859a 100644
--- a/dev/ci/cases/pr/C96C48_hybatmDA.yaml
+++ b/dev/ci/cases/pr/C96C48_hybatmDA.yaml
@@ -8,7 +8,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122018
   edate: 2021122106
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48_hybatmsnowDA.yaml b/dev/ci/cases/pr/C96C48_hybatmsnowDA.yaml
index ad136129a3d..6c1412a229b 100644
--- a/dev/ci/cases/pr/C96C48_hybatmsnowDA.yaml
+++ b/dev/ci/cases/pr/C96C48_hybatmsnowDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48_hybatmsoilDA.yaml b/dev/ci/cases/pr/C96C48_hybatmsoilDA.yaml
index 9c4c60d2fc8..11b8f6f6668 100644
--- a/dev/ci/cases/pr/C96C48_hybatmsoilDA.yaml
+++ b/dev/ci/cases/pr/C96C48_hybatmsoilDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808/
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2022051506
   edate: 2022051518
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48_ufs_hybatmDA.yaml b/dev/ci/cases/pr/C96C48_ufs_hybatmDA.yaml
index 41937cf88bb..d122a452038 100644
--- a/dev/ci/cases/pr/C96C48_ufs_hybatmDA.yaml
+++ b/dev/ci/cases/pr/C96C48_ufs_hybatmDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2024022318
   edate: 2024022406
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48_ufsgsi_hybatmDA.yaml b/dev/ci/cases/pr/C96C48_ufsgsi_hybatmDA.yaml
index dd81c485f8e..cbe5abba619 100644
--- a/dev/ci/cases/pr/C96C48_ufsgsi_hybatmDA.yaml
+++ b/dev/ci/cases/pr/C96C48_ufsgsi_hybatmDA.yaml
@@ -7,7 +7,7 @@ experiment:
   resensatmos: 48
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2024022318
   edate: 2024022406
   nens: 2
diff --git a/dev/ci/cases/pr/C96C48mx500_S2SW_cyc_gfs.yaml b/dev/ci/cases/pr/C96C48mx500_S2SW_cyc_gfs.yaml
index b70f88ccb13..8c643a0a5d4 100644
--- a/dev/ci/cases/pr/C96C48mx500_S2SW_cyc_gfs.yaml
+++ b/dev/ci/cases/pr/C96C48mx500_S2SW_cyc_gfs.yaml
@@ -8,7 +8,7 @@ experiment:
   resdetocean: 5.0
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 2
diff --git a/dev/ci/cases/pr/C96_atm3DVar.yaml b/dev/ci/cases/pr/C96_atm3DVar.yaml
index ef5bebbd54d..cf18207fa88 100644
--- a/dev/ci/cases/pr/C96_atm3DVar.yaml
+++ b/dev/ci/cases/pr/C96_atm3DVar.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122018
   edate: 2021122106
   nens: 0
diff --git a/dev/ci/cases/pr/C96_atm3DVar_extended.yaml b/dev/ci/cases/pr/C96_atm3DVar_extended.yaml
index f62dc7a49b4..48c3e558408 100644
--- a/dev/ci/cases/pr/C96_atm3DVar_extended.yaml
+++ b/dev/ci/cases/pr/C96_atm3DVar_extended.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122018
   edate: 2021122118
   nens: 0
diff --git a/dev/ci/cases/pr/C96_gcafs_cycled.yaml b/dev/ci/cases/pr/C96_gcafs_cycled.yaml
index 674dc788251..fe78983dad2 100644
--- a/dev/ci/cases/pr/C96_gcafs_cycled.yaml
+++ b/dev/ci/cases/pr/C96_gcafs_cycled.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/pr/C96_gcafs_cycled_noDA.yaml b/dev/ci/cases/pr/C96_gcafs_cycled_noDA.yaml
index 1b7a40528be..d5788e5b4c3 100644
--- a/dev/ci/cases/pr/C96_gcafs_cycled_noDA.yaml
+++ b/dev/ci/cases/pr/C96_gcafs_cycled_noDA.yaml
@@ -6,7 +6,7 @@ experiment:
   resdetatmos: 96
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96C48/20250808
+  icsdir: {{ BASE_IC }}/C96C48/20250808
   idate: 2021122012
   edate: 2021122100
   nens: 0
diff --git a/dev/ci/cases/pr/C96mx100_S2S.yaml b/dev/ci/cases/pr/C96mx100_S2S.yaml
index 41a8242995b..96297d5a9cd 100644
--- a/dev/ci/cases/pr/C96mx100_S2S.yaml
+++ b/dev/ci/cases/pr/C96mx100_S2S.yaml
@@ -12,7 +12,7 @@ experiment:
   nens: 2
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96mx100/20250808
+  icsdir: {{ BASE_IC }}/C96mx100/20250808
   yaml: {{ HOMEglobal }}/dev/ci/cases/yamls/sfs_defaults.yaml
 
 skip_ci_on_hosts:
diff --git a/dev/ci/cases/sfsv1/C96mx025_S2S.yaml b/dev/ci/cases/sfsv1/C96mx025_S2S.yaml
index 829419ed6b6..3cd39bcef44 100644
--- a/dev/ci/cases/sfsv1/C96mx025_S2S.yaml
+++ b/dev/ci/cases/sfsv1/C96mx025_S2S.yaml
@@ -12,7 +12,7 @@ experiment:
   nens: 2
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96mx025/20251217
+  icsdir: {{ BASE_IC }}/C96mx025/20251217
   yaml: {{ HOMEglobal }}/dev/ci/cases/yamls/sfs_CPC_defaults.yaml
 
 skip_ci_on_hosts:
diff --git a/dev/ci/cases/sfsv1/C96mx100_S2S.yaml b/dev/ci/cases/sfsv1/C96mx100_S2S.yaml
index 5f68fc1ac46..2db7be8f72a 100644
--- a/dev/ci/cases/sfsv1/C96mx100_S2S.yaml
+++ b/dev/ci/cases/sfsv1/C96mx100_S2S.yaml
@@ -12,7 +12,7 @@ experiment:
   nens: 10
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C96mx100/20240610
+  icsdir: {{ BASE_IC }}/C96mx100/20240610
   yaml: {{ HOMEglobal }}/dev/ci/cases/yamls/sfs_full.yaml
 
 workflow:
diff --git a/dev/ci/cases/weekly/C384C192_hybatmda.yaml b/dev/ci/cases/weekly/C384C192_hybatmda.yaml
index 2b85317114b..f1c507c3a2c 100644
--- a/dev/ci/cases/weekly/C384C192_hybatmda.yaml
+++ b/dev/ci/cases/weekly/C384C192_hybatmda.yaml
@@ -8,7 +8,7 @@ experiment:
   resensatmos: 192
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C384C192/20240610
+  icsdir: {{ BASE_IC }}/C384C192/20240610
   idate: 2023040118
   edate: 2023040200
   nens: 2
diff --git a/dev/ci/cases/weekly/C384_atm3DVar.yaml b/dev/ci/cases/weekly/C384_atm3DVar.yaml
index 740e7f99825..b3d3a53d072 100644
--- a/dev/ci/cases/weekly/C384_atm3DVar.yaml
+++ b/dev/ci/cases/weekly/C384_atm3DVar.yaml
@@ -8,7 +8,7 @@ experiment:
   resensatmos: 192
   comroot: {{ 'RUNTESTS' | getenv }}/COMROOT
   expdir: {{ 'RUNTESTS' | getenv }}/EXPDIR
-  icsdir: {{ 'ICSDIR_ROOT' | getenv }}/C384C192/20240610
+  icsdir: {{ BASE_IC }}/C384C192/20240610
   idate: 2023040118
   edate: 2023040200
   nens: 0
diff --git a/dev/ci/platforms/config.gaeac6 b/dev/ci/platforms/config.gaeac6
index 5b06b46f4f9..f7468354517 100644
--- a/dev/ci/platforms/config.gaeac6
+++ b/dev/ci/platforms/config.gaeac6
@@ -10,9 +10,9 @@
 # Main CI root directory - Base directory for all CI/CD operations
 export GFS_CI_ROOT="/gpfs/f6/drsa-precip3/proj-shared/${USER}/GFS_CI_CD"
 
-# ICSDIR root directory - Contains initial condition data
-# Used by create_experiment.py for setting up test cases
-export ICSDIR_ROOT=/gpfs/f6/drsa-precip3/world-shared/role.glopara/data/ICSDIR
+# BASE_IC directory - Platform home for staged initial conditions
+# Used by case yaml files for setting up the IC path
+export BASE_IC=/gpfs/f6/drsa-precip3/world-shared/role.glopara/data/ICSDIR
 
 #########################################################################
 # Jenkins configuration settings
diff --git a/dev/ci/platforms/config.hera b/dev/ci/platforms/config.hera
index 6b846ca52ed..9baec74704d 100644
--- a/dev/ci/platforms/config.hera
+++ b/dev/ci/platforms/config.hera
@@ -12,9 +12,9 @@
 # main path to establish a unique path
 export GFS_CI_ROOT=/scratch3/NCEPDEV/global/role.glopara/GFS_CI_CD/HERA
 
-# ICSDIR root directory - Contains initial condition data
-# Used by create_experiment.py for setting up test cases
-export ICSDIR_ROOT=/scratch3/NCEPDEV/global/role.glopara/data/ICSDIR
+# BASE_IC directory - Platform home for staged initial conditions
+# Used by case yaml files for setting up the IC path
+export BASE_IC=/scratch3/NCEPDEV/global/role.glopara/data/ICSDIR
 
 
 #########################################################################
diff --git a/dev/ci/platforms/config.hercules b/dev/ci/platforms/config.hercules
index 0b1bb6f15e4..50ff747a992 100644
--- a/dev/ci/platforms/config.hercules
+++ b/dev/ci/platforms/config.hercules
@@ -10,9 +10,9 @@
 # Main CI root directory
 export GFS_CI_ROOT=/work2/noaa/global/role-global/GFS_CI_CD/HERCULES
 
-# ICSDIR root directory - Contains initial condition data
-# Used by create_experiment.py for setting up test cases
-export ICSDIR_ROOT=/work/noaa/global/glopara/data/ICSDIR
+# BASE_IC directory - Platform home for staged initial conditions
+# Used by case yaml files for setting up the IC path
+export BASE_IC=/work2/noaa/global/role-global/data/ICSDIR
 
 #########################################################################
 # Jenkins configuration settings
diff --git a/dev/ci/platforms/config.orion b/dev/ci/platforms/config.orion
index 32af60cef84..724f3abbabd 100644
--- a/dev/ci/platforms/config.orion
+++ b/dev/ci/platforms/config.orion
@@ -10,9 +10,9 @@
 # Main CI root directory
 export GFS_CI_ROOT=/work2/noaa/global/${USER}/GFS_CI_CD/ORION
 
-# ICSDIR root directory - Contains initial condition data
-# Used by create_experiment.py for setting up test cases
-export ICSDIR_ROOT=/work/noaa/global/glopara/data/ICSDIR
+# BASE_IC directory - Platform home for staged initial conditions
+# Used by case yaml files for setting up the IC path
+export BASE_IC=/work2/noaa/global/role-global/data/ICSDIR
 
 #########################################################################
 # Jenkins configuration settings
diff --git a/dev/ci/platforms/config.ursa b/dev/ci/platforms/config.ursa
index 0a9e6dfd61a..3672db4a0ec 100644
--- a/dev/ci/platforms/config.ursa
+++ b/dev/ci/platforms/config.ursa
@@ -12,9 +12,9 @@
 # main path to establish a unique path
 export GFS_CI_ROOT=/scratch3/NCEPDEV/global/role.glopara/GFS_CI_CD/URSA
 
-# ICSDIR root directory - Contains initial condition data
-# Used by create_experiment.py for setting up test cases
-export ICSDIR_ROOT=/scratch3/NCEPDEV/global/role.glopara/data/ICSDIR
+# BASE_IC directory - Platform home for staged initial conditions
+# Used by case yaml files for setting up the IC path
+export BASE_IC=/scratch3/NCEPDEV/global/role.glopara/data/ICSDIR
 
 
 #########################################################################
diff --git a/dev/ci/platforms/config.wcoss2 b/dev/ci/platforms/config.wcoss2
index 2d461a8256a..ecbb8c5e4dc 100644
--- a/dev/ci/platforms/config.wcoss2
+++ b/dev/ci/platforms/config.wcoss2
@@ -1,7 +1,7 @@
 #!/usr/bin/bash
 
 export GFS_CI_ROOT=/lfs/h2/emc/global/noscrub/globalworkflow.ci/GFS_CI_ROOT
-export ICSDIR_ROOT=/lfs/h2/emc/global/noscrub/emc.global/data/ICSDIR
+export BASE_IC=/lfs/h2/emc/global/noscrub/emc.global/data/ICSDIR
 # HPC account which overides the default account
 export HPC_ACCOUNT=${HPC_ACCOUNT:-GFS-DEV}
 
diff --git a/dev/ci/scripts/unittests/test_create_experiment.py b/dev/ci/scripts/unittests/test_create_experiment.py
index 6f58385b9b6..92c9fd43322 100644
--- a/dev/ci/scripts/unittests/test_create_experiment.py
+++ b/dev/ci/scripts/unittests/test_create_experiment.py
@@ -6,7 +6,6 @@
 HOMEglobal = find_upward('.github')
 current_dir = os.path.dirname(os.path.abspath(__file__))
 RUNDIR_FAKE = os.path.join(current_dir, 'testdata/RUNTESTS')
-ICSDIR_FAKE = os.path.join(current_dir, 'testdata/ICSDIR')
 
 
 def test_create_experiment():
@@ -16,7 +15,6 @@ def test_create_experiment():
     yaml_dir = yaml_dir = os.path.join(HOMEglobal, 'dev/ci/cases/pr')
     env = os.environ.copy()
     env['RUNTESTS'] = RUNDIR_FAKE
-    env['ICSDIR_ROOT'] = ICSDIR_FAKE
 
     err = 0
     for case in os.listdir(yaml_dir):
diff --git a/dev/ctests/CMakeLists.txt b/dev/ctests/CMakeLists.txt
index 62d25f8ace3..e30f214ecf4 100644
--- a/dev/ctests/CMakeLists.txt
+++ b/dev/ctests/CMakeLists.txt
@@ -39,17 +39,10 @@ if (NOT DEFINED STAGED_CTESTS)
   return()
 endif()
 
-# Set ICSDIR_ROOT
-set_from_env_or_default(ICSDIR_ROOT ICSDIR_ROOT "")
-if (NOT DEFINED ICSDIR_ROOT)
-  message(WARNING "ICSDIR_ROOT must be set. CTests will not be created.")
-  return()
-endif()
 
 message(STATUS "gw: global-workflow baselines will be used from: '${HOMEglobal}'")
 message(STATUS "gw: global-workflow tests will be run at: '${RUNTESTS}'")
 message(STATUS "gw: global-workflow tests will use the allocation: '${HPC_ACCOUNT}'")
-message(STATUS "gw: global-workflow tests will use ICSDIR_ROOT: '${ICSDIR_ROOT}'")
 
 # Prepare test scripts
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/setup.sh.in
diff --git a/dev/ctests/README.md b/dev/ctests/README.md
index e4654ac25fe..fb7b3de11e4 100644
--- a/dev/ctests/README.md
+++ b/dev/ctests/README.md
@@ -13,7 +13,6 @@ The following environment variables must be set (either in your environment or v
 ```bash
 HPC_ACCOUNT       # Your HPC allocation account
 STAGED_CTESTS     # Path to nightly baseline COMROOT
-ICSDIR_ROOT       # Path to initial condition files
 ```
 
 These are typically defined in `$HOMEglobal/dev/ci/platforms/config.$MACHINE_ID`.
@@ -31,7 +30,6 @@ cmake ../../..
 # Or configure with explicit command-line options
 cmake -DHPC_ACCOUNT=myaccount \
       -DSTAGED_CTESTS=/path/to/baselines/RUNTESTS \
-      -DICSDIR_ROOT=/path/to/ics \
       ../../..
 ```
 
@@ -242,7 +240,7 @@ Platform-specific settings are in `$HOMEglobal/dev/ci/platforms/config.$MACHINE_
 export GFS_CI_ROOT=/scratch1/NCEPDEV/global/Terry.McGuinness/GFS_CI_ROOT
 export GITLAB_BUILDS_DIR=${GFS_CI_ROOT}/BUILDS/GITLAB
 export STAGED_CTESTS=${GITLAB_BUILDS_DIR}/stable/RUNTESTS
-export ICSDIR_ROOT=/scratch1/NCEPDEV/global/glopara/data/ICSDIR
+export BASE_IC=/scratch1/NCEPDEV/global/glopara/data/ICSDIR
 export HPC_ACCOUNT=nems
 ```
 
diff --git a/dev/ctests/scripts/setup.sh.in b/dev/ctests/scripts/setup.sh.in
index ed6e7ab014c..5d2bcab73b9 100755
--- a/dev/ctests/scripts/setup.sh.in
+++ b/dev/ctests/scripts/setup.sh.in
@@ -8,7 +8,6 @@ YAML_FILE=${2:?"Name of the CI yaml file for the test"}
 # CMake to fill these variables
 HOMEglobal="@PROJECT_SOURCE_DIR@"
 RUNTESTS="@RUNTESTS@"
-ICSDIR_ROOT="@ICSDIR_ROOT@"
 HPC_ACCOUNT="@HPC_ACCOUNT@"
 
 set +x
@@ -24,7 +23,6 @@ sha=$(git rev-parse --short HEAD)
 
 pslot="${TEST_NAME}_${sha}" \
 RUNTESTS="${RUNTESTS}" \
-ICSDIR_ROOT="${ICSDIR_ROOT}" \
 HPC_ACCOUNT="${HPC_ACCOUNT}" \
 ./create_experiment.py --yaml "${YAML_FILE}" --overwrite
 rc=$?
diff --git a/dev/workflow/create_experiment.py b/dev/workflow/create_experiment.py
index 584ddab6f27..0f9e1358de1 100755
--- a/dev/workflow/create_experiment.py
+++ b/dev/workflow/create_experiment.py
@@ -34,6 +34,7 @@
 
 import setup_expt
 import setup_workflow
+from hosts import Host
 
 
 _here = os.path.dirname(__file__)
@@ -85,7 +86,11 @@ def input_args():
     user_inputs = input_args()
 
     # Create a dictionary to pass to parse_j2yaml for parsing the yaml file
+    # Load host info first so host variables (e.g. BASE_IC) are available as
+    # template variables when the case YAML is rendered.
+    host = Host()
     data = AttrDict(HOMEglobal=_top)
+    data.update(host.info)
     data.update(os.environ)
     testconf = parse_j2yaml(path=user_inputs.yaml, data=data)
 
diff --git a/dev/workflow/generate_workflows.sh b/dev/workflow/generate_workflows.sh
index b2cfd404ec2..8b2d39f3837 100755
--- a/dev/workflow/generate_workflows.sh
+++ b/dev/workflow/generate_workflows.sh
@@ -57,6 +57,10 @@ function _usage() {
        \$HOMEglobal/dev/ci/platform/config.\$machine
        will be used.
 
+    -I "/path/to/base_ic"  Override BASE_IC for all cases.
+       If this is not set, BASE_IC is read from the hosts YAML
+       (\$HOMEglobal/dev/workflow/hosts/\$machine.yaml).
+
     -c Append the chosen set of tests to your existing crontab
        If this option is not chosen, the new entries that would have been
        written to your crontab will be printed to stdout.
@@ -83,6 +87,9 @@ EOF
 
 set -eu
 
+# --------------------------------------------------------------------------- #
+# Defaults and Runtime State
+# --------------------------------------------------------------------------- #
 # Set default options
 HOMEglobal=""
 _specified_home=false
@@ -100,6 +107,8 @@ _run_all_sfs=false
 _run_all_gcafs=false
 _hpc_account=""
 _set_account=false
+_base_ic=""
+_set_base_ic=false
 _update_cron=false
 _email=""
 _tag=""
@@ -112,71 +121,100 @@ _cwd=$(pwd)
 _runtests="${RUNTESTS:-${_runtests:-}}"
 _auto_del=false
 _nonflag_option_count=0
+# --------------------------------------------------------------------------- #
+# Argument Parsing
+# --------------------------------------------------------------------------- #
+
+function _set_yaml_list_from_arg() {
+    # Start over with an empty list and normalize names to no .yaml suffix.
+    declare -a _yaml_list=()
+    for _yaml in ${OPTARG}; do
+        _yaml_list+=("${_yaml//.yaml/}")
+    done
+    _specified_yaml_list=true
+}
 
-while [[ $# -gt 0 && "$1" != "--" ]]; do
-    while getopts ":H:bBDuy:Y:GESCA:ce:t:vVdh" option; do
-        case "${option}" in
-            H)
-                HOMEglobal="${OPTARG}"
-                _specified_home=true
-                if [[ ! -d "${HOMEglobal}" ]]; then
-                    echo "Specified HOMEglobal directory (${HOMEglobal}) does not exist"
-                    exit 1
-                fi
-                ;;
-            b) _build=true ;;
-            B) _build=true && _compute_build=true ;;
-            D) _auto_del=true ;;
-            u) _update_submods=true ;;
-            y) # Start over with an empty _yaml_list
-                declare -a _yaml_list=()
-                for _yaml in ${OPTARG}; do
-                    # Strip .yaml from the end of each and append to _yaml_list
-                    _yaml_list+=("${_yaml//.yaml/}")
-                done
-                _specified_yaml_list=true
-                ;;
-            Y) _yaml_dir="${OPTARG}" && _specified_yaml_dir=true ;;
-            G) _run_all_gfs=true ;;
-            E) _run_all_gefs=true ;;
-            S) _run_all_sfs=true ;;
-            C) _run_all_gcafs=true ;;
-            c) _update_cron=true ;;
-            e) _email="${OPTARG}" && _set_email=true ;;
-            t) _tag="_${OPTARG}" ;;
-            v) _verbose=true ;;
-            V) _very_verbose=true && _verbose=true && _verbose_flag="-v" ;;
-            A) _set_account=true && _hpc_account="${OPTARG}" ;;
-            d) _debug=true && _very_verbose=true && _verbose=true && _verbose_flag="-v" && PS4='${LINENO}: ' ;;
-            h) _usage && exit 0 ;;
-            :)
-                echo "[${BASH_SOURCE[0]}]: ${option} requires an argument"
-                _usage
-                exit 1
-                ;;
-            *)
-                echo "[${BASH_SOURCE[0]}]: Unrecognized option: ${option}"
-                _usage
+function _parse_option() {
+    case "${option}" in
+        # Core paths and build mode
+        H)
+            HOMEglobal="${OPTARG}"
+            _specified_home=true
+            if [[ ! -d "${HOMEglobal}" ]]; then
+                echo "Specified HOMEglobal directory (${HOMEglobal}) does not exist"
                 exit 1
-                ;;
-        esac
-    done
+            fi
+            ;;
+        b) _build=true ;;
+        B) _build=true && _compute_build=true ;;
+        D) _auto_del=true ;;
+        u) _update_submods=true ;;
+
+        # Test/case selection
+        y) _set_yaml_list_from_arg ;;
+        Y) _yaml_dir="${OPTARG}" && _specified_yaml_dir=true ;;
+        G) _run_all_gfs=true ;;
+        E) _run_all_gefs=true ;;
+        S) _run_all_sfs=true ;;
+        C) _run_all_gcafs=true ;;
+
+        # Workflow behavior and notifications
+        c) _update_cron=true ;;
+        e) _email="${OPTARG}" && _set_email=true ;;
+        t) _tag="_${OPTARG}" ;;
+        I) _set_base_ic=true && _base_ic="${OPTARG}" ;;
+
+        # Logging/debug
+        v) _verbose=true ;;
+        V) _very_verbose=true && _verbose=true && _verbose_flag="-v" ;;
+        d) _debug=true && _very_verbose=true && _verbose=true && _verbose_flag="-v" && PS4='${LINENO}: ' ;;
+
+        # HPC account and usage
+        A) _set_account=true && _hpc_account="${OPTARG}" ;;
+        h) _usage && exit 0 ;;
+
+        :)
+            echo "[${BASH_SOURCE[0]}]: ${option} requires an argument"
+            _usage
+            exit 1
+            ;;
+        *)
+            echo "[${BASH_SOURCE[0]}]: Unrecognized option: ${option}"
+            _usage
+            exit 1
+            ;;
+    esac
+}
 
-    if [[ ${OPTIND:-0} -gt 0 ]]; then
-        shift $((OPTIND - 1))
-    fi
+function _parse_args() {
+    while [[ $# -gt 0 && "$1" != "--" ]]; do
+        while getopts ":H:bBDuy:Y:GESCA:I:ce:t:vVdh" option; do
+            _parse_option
+        done
 
-    while [[ $# -gt 0 && ! "$1" =~ ^- ]]; do
-        _runtests=${1}
-        ((_nonflag_option_count += 1))
-        if [[ ${_nonflag_option_count} -gt 1 ]]; then
-            echo "Too many arguments specified."
-            _usage
-            exit 2
+        if [[ ${OPTIND:-0} -gt 0 ]]; then
+            shift $((OPTIND - 1))
+            OPTIND=1
         fi
-        shift
+
+        while [[ $# -gt 0 && ! "$1" =~ ^- ]]; do
+            _runtests=${1}
+            ((_nonflag_option_count += 1))
+            if [[ ${_nonflag_option_count} -gt 1 ]]; then
+                echo "Too many arguments specified."
+                _usage
+                exit 2
+            fi
+            shift
+        done
     done
-done
+}
+
+_parse_args "$@"
+
+# --------------------------------------------------------------------------- #
+# Common Helpers
+# --------------------------------------------------------------------------- #
 
 function send_email() {
     # Send an email to $_email.
@@ -226,6 +264,10 @@ function delete_dir() {
     done
 }
 
+# --------------------------------------------------------------------------- #
+# Validate Required Inputs
+# --------------------------------------------------------------------------- #
+
 if [[ -z "${_runtests}" ]]; then
     echo "Missing run directory (RUNTESTS) argument/environment variable."
     sleep 2
@@ -238,6 +280,10 @@ if [[ "${_debug}" == "true" ]]; then
     set -x
 fi
 
+# --------------------------------------------------------------------------- #
+# Prepare RUNTESTS Directory
+# --------------------------------------------------------------------------- #
+
 # Create the RUNTESTS directory
 # Start by getting the full path
 _runtests="$(realpath "${_runtests}")"
@@ -262,6 +308,10 @@ else
     fi
 fi
 
+# --------------------------------------------------------------------------- #
+# Resolve Initial Case Selection
+# --------------------------------------------------------------------------- #
+
 # Empty the _yaml_list array if -G, -E, -S and/or -C were selected
 if [[ "${_run_all_gfs}" == "true" ||
     "${_run_all_gefs}" == "true" ||
@@ -293,6 +343,10 @@ if [[ "${_specified_yaml_dir}" == false ]]; then
     _yaml_dir="${HOMEglobal}/dev/ci/cases/pr"
 fi
 
+# --------------------------------------------------------------------------- #
+# Case Discovery Helper
+# --------------------------------------------------------------------------- #
+
 function select_all_yamls() {
     # A helper function to select all of the YAMLs for a specified system (gfs, gefs, sfs)
 
@@ -355,6 +409,10 @@ EOM
     fi
 }
 
+# --------------------------------------------------------------------------- #
+# Expand Case List By System Flags
+# --------------------------------------------------------------------------- #
+
 # Check if running all GEFS cases
 if [[ "${_run_all_gefs}" == "true" ]]; then
     # Append -w to build_all.sh flags if -E was specified
@@ -392,6 +450,10 @@ if [[ "${_run_all_gcafs}" == "true" ]]; then
     _yaml_list=("${_yaml_list[@]}" "${_gcafs_yaml_list[@]}")
 fi
 
+# --------------------------------------------------------------------------- #
+# Optional Submodule Update
+# --------------------------------------------------------------------------- #
+
 # Update submodules if requested
 if [[ "${_update_submods}" == "true" ]]; then
     printf "Updating submodules\n\n"
@@ -418,6 +480,10 @@ EOM
     fi
 fi
 
+# --------------------------------------------------------------------------- #
+# Load Workflow Environment
+# --------------------------------------------------------------------------- #
+
 # Loading modules sometimes raises unassigned errors, so disable checks
 set +u
 if [[ "${_verbose}" == "true" ]]; then
@@ -440,26 +506,49 @@ if [[ "${_debug}" == "true" ]]; then
 fi
 set -u
 machine=${MACHINE_ID}
-platform_config="${HOMEglobal}/dev/ci/platforms/config.${machine}"
-if [[ -f "${platform_config}" ]]; then
-    source "${HOMEglobal}/dev/ci/platforms/config.${machine}"
-else
-    if [[ "${_set_account}" == "false" ]]; then
-        echo "ERROR Unknown HPC account!  Please use the -A option to specify."
-        exit 11
-    fi
-fi
 
 # If _yaml_dir is not set, set it to $HOMEglobal/dev/ci/cases/pr
 if [[ -z ${_yaml_dir} ]]; then
     _yaml_dir="${HOMEglobal}/dev/ci/cases/pr"
 fi
 
+# --------------------------------------------------------------------------- #
+# Resolve HPC Account
+# --------------------------------------------------------------------------- #
+
+# Update the account: -A flag > existing env var > platform config default
+if [[ "${_set_account}" == true ]]; then
+    export HPC_ACCOUNT="${_hpc_account}"
+    if [[ "${_verbose}" == true ]]; then
+        printf "Setting HPC account to %s\n\n" "${HPC_ACCOUNT}"
+    fi
+elif [[ -z "${HPC_ACCOUNT:-}" ]]; then
+    platform_config="${HOMEglobal}/dev/ci/platforms/config.${machine}"
+    if [[ -f "${platform_config}" ]]; then
+        _platform_account=$(sed -n "s/^export HPC_ACCOUNT=\${HPC_ACCOUNT:-\([^}]*\)}.*/\1/p" "${platform_config}")
+        export HPC_ACCOUNT="${_platform_account}"
+        if [[ "${_verbose}" == true ]]; then
+            printf "Setting HPC account to %s from platform config\n\n" "${HPC_ACCOUNT}"
+        fi
+    else
+        echo "ERROR Unknown HPC account! Please use the -A option to specify."
+        exit 11
+    fi
+fi
+
+# --------------------------------------------------------------------------- #
+# Build and Link Workflow
+# --------------------------------------------------------------------------- #
+
 # Build the system if requested
 if [[ "${_build}" == "true" ]]; then
     printf "Building via build_all.sh %s\n\n" "${_build_flags}"
     # Let the output of build_all.sh go to stdout regardless of verbose options
     if [[ "${_compute_build}" == true ]]; then
+        if [[ -z "${HPC_ACCOUNT:-}" ]]; then
+            echo "ERROR Unknown HPC account!  Please use the -A option to specify."
+            exit 11
+        fi
         _compute_build_flag="-c -A ${HPC_ACCOUNT}"
     fi
     #shellcheck disable=SC2086,SC2248
@@ -482,6 +571,10 @@ if ! "${HOMEglobal}/sorc/link_workflow.sh" >&stdout; then
 fi
 rm -f stdout
 
+# --------------------------------------------------------------------------- #
+# Validate YAML Inputs For This Host
+# --------------------------------------------------------------------------- #
+
 # Configure the environment for running create_experiment.py
 if [[ "${_verbose}" == true ]]; then
     printf "Setting up the environment to run create_experiment.py\n\n"
@@ -521,14 +614,22 @@ EOM
     done
 done
 
-# Update the account if specified
-if [[ "${_set_account}" == true ]]; then
-    export HPC_ACCOUNT=${_hpc_account}
+# --------------------------------------------------------------------------- #
+# Apply BASE_IC Override
+# --------------------------------------------------------------------------- #
+
+# Override BASE_IC if specified via -I
+if [[ "${_set_base_ic}" == true ]]; then
+    export BASE_IC="${_base_ic}"
     if [[ "${_verbose}" == true ]]; then
-        printf "Setting HPC account to %s\n\n" "${HPC_ACCOUNT}"
+        printf "Overriding BASE_IC to %s\n\n" "${BASE_IC}"
     fi
 fi
 
+# --------------------------------------------------------------------------- #
+# Create Experiments and Collect Schedule Entries
+# --------------------------------------------------------------------------- #
+
 # Create the experiments
 rm -f "tests.cron" "${_verbose_flag}"
 echo "Running create_experiment.py for ${#_yaml_list[@]} cases"
@@ -606,6 +707,10 @@ for _case in "${_yaml_list[@]}"; do
 done
 echo
 
+# --------------------------------------------------------------------------- #
+# Configure Mail Behavior
+# --------------------------------------------------------------------------- #
+
 # Add MAILTO to tests.cron for regular crontab
 if [[ "${_use_scron}" == false ]]; then
     if [[ "${_set_email}" == "true" ]]; then
@@ -620,6 +725,10 @@ if [[ "${_use_scron}" == false ]]; then
     fi
 fi
 
+# --------------------------------------------------------------------------- #
+# Install or Print Scheduler Entries
+# --------------------------------------------------------------------------- #
+
 # Update the cron
 if [[ "${_update_cron}" == "true" ]]; then
     printf "Updating the existing crontab\n\n"
@@ -698,6 +807,10 @@ else
     fi
 fi
 
+# --------------------------------------------------------------------------- #
+# Cleanup and Completion
+# --------------------------------------------------------------------------- #
+
 # Cleanup
 if [[ "${_debug}" == "false" ]]; then
     rm -f final.cron existing.cron tests.cron "${_verbose_flag}"
diff --git a/dev/workflow/hosts.py b/dev/workflow/hosts.py
index 2a2fcf42cb6..972053d3a99 100644
--- a/dev/workflow/hosts.py
+++ b/dev/workflow/hosts.py
@@ -32,6 +32,7 @@ def __init__(self, host=None):
             self.detect()
 
         self.info = self._get_info
+        self._apply_env_overrides(self.info)
         self.scheduler = self.info['SCHEDULER']
 
     def __str__(self) -> str:
@@ -103,6 +104,19 @@ def detect(self) -> None:
                                   'Currently supported hosts are:\n' +
                                   f'{" | ".join(Host.SUPPORTED_HOSTS)}')
 
+    def _apply_env_overrides(self, info: dict) -> None:
+        """Override host configuration values with environment variables.
+
+        Parameters
+        ----------
+        info : dict
+            Host configuration dictionary to update in-place.
+        """
+        # Allow BASE_IC to be overridden via the environment
+        # (e.g. from the -I flag in generate_workflows.sh)
+        if 'BASE_IC' in os.environ:
+            info['BASE_IC'] = os.environ['BASE_IC']
+
     @property
     def _get_info(self) -> dict:
 
diff --git a/ush/postamble.sh b/ush/postamble.sh
index b26ead789a2..dd9ebd74cd1 100644
--- a/ush/postamble.sh
+++ b/ush/postamble.sh
@@ -22,9 +22,9 @@ postamble() {
     #     rc:         exit code of the script [default: $?]
     #
 
+    local rc="${2:-$?}" # Capture exit code FIRST, before set +x clobbers $?
     set +x
     local start_time="${1}"
-    local rc="${2:-$?}"
 
     # Execute any commands registered in POSTAMBLE_CMD
     #