diff --git a/.gitignore b/.gitignore
index e92da48887..7e286433ca 100644
--- a/.gitignore
+++ b/.gitignore
@@ -176,6 +176,7 @@ ush/global_cycle_driver.sh
 ush/gsi_satbias2ioda_all.sh
 ush/jediinc2fv3.py
 ush/imsfv3_scf2ioda.py
+ush/ghcn_snod2ioda.py
 ush/bufr_snocvr_snomad.py
 ush/atparse.bash
 ush/bufr2ioda_insitu*
diff --git a/dev/parm/config/gfs/config.esnowanl.j2 b/dev/parm/config/gfs/config.esnowanl.j2
index 786a450858..086b3620e9 100644
--- a/dev/parm/config/gfs/config.esnowanl.j2
+++ b/dev/parm/config/gfs/config.esnowanl.j2
@@ -8,15 +8,19 @@ echo "BEGIN: config.esnowanl"
 # Get task specific resources
 source "${EXPDIR}/config.resources" esnowanl
 
-export TASK_CONFIG_YAML="${PARMgfs}/gdas/snow/snow_ens_config.yaml.j2"
-export OBS_LIST_YAML="${PARMgfs}/gdas/snow/snow_obs_list.yaml.j2"
-
 # Name of the executable that applies increment to bkg and its namelist template
 export APPLY_INCR_EXE="${EXECgfs}/gdas_apply_incr.x"
 export ENS_APPLY_INCR_NML_TMPL="${PARMgfs}/gdas/snow/ens_apply_incr_nml.j2"
 
+export TASK_CONFIG_YAML="${PARMgfs}/gdas/snow/snow_ens_config.yaml.j2"
+export OBS_LIST_YAML="${PARMgfs}/gdas/snow/snow_obs_list.yaml.j2"
+export ims_scf_obs_suffix="asc" # asc-ascii; nc-netcdf
+export fail_on_missing_snowobs=False    # False: just warn; True: fail & exit
+
 export PREP_SNOCVR_SNOMAD_YAML="${PARMgfs}/gdas/snow/prep/prep_snocvr_snomad.yaml.j2"
 export OBSBUILDER="${USHgfs}/bufr_snocvr_snomad.py"
+export PREP_GHCN_YAML="${PARMgfs}/gdas/snow/prep/prep_ghcn.yaml.j2"
+export GHCN2IODACONV="${USHgfs}/ghcn_snod2ioda.py"
 
 export io_layout_x="{{ IO_LAYOUT_X }}"
 export io_layout_y="{{ IO_LAYOUT_Y }}"
diff --git a/dev/parm/config/gfs/config.snowanl.j2 b/dev/parm/config/gfs/config.snowanl.j2
index b88cb42976..a76e584246 100644
--- a/dev/parm/config/gfs/config.snowanl.j2
+++ b/dev/parm/config/gfs/config.snowanl.j2
@@ -14,9 +14,13 @@ export APPLY_INCR_NML_TMPL="${PARMgfs}/gdas/snow/apply_incr_nml.j2"
 
 export TASK_CONFIG_YAML="${PARMgfs}/gdas/snow/snow_det_config.yaml.j2"
 export OBS_LIST_YAML="${PARMgfs}/gdas/snow/snow_obs_list.yaml.j2"
+export ims_scf_obs_suffix="asc" # asc-ascii; nc-netcdf
+export fail_on_missing_snowobs=False    # False: just warn; True: fail & exit
 
 export PREP_SNOCVR_SNOMAD_YAML="${PARMgfs}/gdas/snow/prep/prep_snocvr_snomad.yaml.j2"
 export OBSBUILDER="${USHgfs}/bufr_snocvr_snomad.py"
+export PREP_GHCN_YAML="${PARMgfs}/gdas/snow/prep/prep_ghcn.yaml.j2"
+export GHCN2IODACONV="${USHgfs}/ghcn_snod2ioda.py"
 
 export io_layout_x="{{ IO_LAYOUT_X }}"
 export io_layout_y="{{ IO_LAYOUT_Y }}"
diff --git a/dev/scripts/exglobal_analysis_stats.py b/dev/scripts/exglobal_analysis_stats.py
index 3497a8afc0..8f7eb79b50 100755
--- a/dev/scripts/exglobal_analysis_stats.py
+++ b/dev/scripts/exglobal_analysis_stats.py
@@ -31,11 +31,15 @@
     else:
         config.STAT_ANALYSES.append('atmos_gsi')
 
+    # GCDAS uses offline GDAS, remove atmos analysis
+    if config.RUN == 'gcdas':
+        config.STAT_ANALYSES = [anl for anl in config.STAT_ANALYSES if 'atmos' not in anl]
+
     # Instantiate the analysis stats task
     AnlStats = AnalysisStats(config)
 
     # Initialize JEDI variational analysis
-    if not config.DO_JEDIATMVAR:
+    if 'atmos_gsi' in config.STAT_ANALYSES:
         AnlStats.convert_gsi_diags()
     AnlStats.initialize()
     for anl in config.STAT_ANALYSES:
diff --git a/dev/scripts/exglobal_snow_analysis.py b/dev/scripts/exglobal_snow_analysis.py
index 9923187d11..dbd443114a 100755
--- a/dev/scripts/exglobal_snow_analysis.py
+++ b/dev/scripts/exglobal_snow_analysis.py
@@ -31,6 +31,10 @@
     if snow_anl.task_config.DO_IMS_SCF:
         snow_anl.execute('scf_to_ioda')
 
+    # Process GHCN (if applicable)
+    if snow_anl.task_config.DO_GHCN:
+        snow_anl.prepare_GHCN()
+
     # Execute JEDI snow analysis
     snow_anl.execute('snowanlvar')
 
diff --git a/dev/scripts/exglobal_snowens_analysis.py b/dev/scripts/exglobal_snowens_analysis.py
index 4ab13d86b9..aa4b44b5f0 100755
--- a/dev/scripts/exglobal_snowens_analysis.py
+++ b/dev/scripts/exglobal_snowens_analysis.py
@@ -37,6 +37,10 @@
     if snow_ens_anl.task_config.DO_IMS_SCF:
         snow_ens_anl.execute('scf_to_ioda')
 
+    # Process GHCN (if applicable)
+    if snow_ens_anl.task_config.DO_GHCN:
+        snow_ens_anl.prepare_GHCN()
+
     # Execute JEDI snow analysis
     snow_ens_anl.execute('snowanlvar')
 
diff --git a/sorc/gdas.cd b/sorc/gdas.cd
index dd911ba37f..3e0593d7de 160000
--- a/sorc/gdas.cd
+++ b/sorc/gdas.cd
@@ -1 +1 @@
-Subproject commit dd911ba37f5c98a03e5e7cf89699d280e79f538b
+Subproject commit 3e0593d7de31944b3aef5330c36f2ddfecba3014
diff --git a/sorc/link_workflow.sh b/sorc/link_workflow.sh
index e995387ef7..76f2a5de5a 100755
--- a/sorc/link_workflow.sh
+++ b/sorc/link_workflow.sh
@@ -275,7 +275,7 @@ if [[ -d "${HOMEgfs}/sorc/gdas.cd/build" ]]; then
     cd "${HOMEgfs}/ush" || exit 1
     ${LINK_OR_COPY} "${HOMEgfs}/sorc/gdas.cd/ush/gsi_satbias2ioda_all.sh" .
     ${LINK_OR_COPY} "${HOMEgfs}/sorc/gdas.cd/ush/snow/bufr_snocvr_snomad.py" .
-    ${LINK_OR_COPY} "${HOMEgfs}/sorc/gdas.cd/build/bin/imsfv3_scf2ioda.py" .
+    ${LINK_OR_COPY} "${HOMEgfs}/sorc/gdas.cd/ush/snow/ghcn_snod2ioda.py" .
 fi
 
 #------------------------------
@@ -439,7 +439,6 @@ fi
 # GDASApp executables
 if [[ -d "${HOMEgfs}/sorc/gdas.cd/install" ]]; then
     cp -f "${HOMEgfs}/sorc/gdas.cd/install/bin"/gdas* ./
-    cp -f "${HOMEgfs}/sorc/gdas.cd/install/bin/calcfIMS.exe" ./gdas_calcfIMS.x
     cp -f "${HOMEgfs}/sorc/gdas.cd/install/bin/apply_incr.exe" ./gdas_apply_incr.x
 fi
 
diff --git a/ush/python/pygfs/task/analysis_stats.py b/ush/python/pygfs/task/analysis_stats.py
index 44c4f9cfca..7b6415657e 100644
--- a/ush/python/pygfs/task/analysis_stats.py
+++ b/ush/python/pygfs/task/analysis_stats.py
@@ -3,6 +3,7 @@
 import os
 import glob
 import gsincdiag_to_ioda.proc_gsi_ncdiag as gsid
+import gsincdiag_to_ioda.combine_obsspace as gsios
 import gzip
 import tarfile
 from logging import getLogger
@@ -11,7 +12,6 @@
 
 from wxflow import (AttrDict,
                     FileHandler,
-                    add_to_datetime, to_timedelta, to_YMDH,
                     parse_j2yaml,
                     logit)
 from pygfs.jedi import Jedi
@@ -198,16 +198,19 @@ def convert_gsi_diags(self) -> None:
         FileHandler({'mkdir': [diag_ioda_dir_ges_path, diag_ioda_dir_anl_path, output_dir_path]}).sync()
         diag_tar_copy_list = []
         for diag in diag_tars:
-            input_tar_basename = f"{self.task_config.APREFIX}{diag}"
+            input_tar_basename = f"{self.task_config.APREFIX}{diag}.tar"
             input_tar = os.path.join(self.task_config.COMIN_ATMOS_ANALYSIS,
-                                     f"{input_tar_basename}.tar")
+                                     input_tar_basename)
             dest = os.path.join(diag_dir_path, input_tar_basename)
             if os.path.exists(input_tar):
+                logger.info(f"{input_tar} exists. Preparing to copy it to {dest}")
                 diag_tar_copy_list.append([input_tar, dest])
+            else:
+                logger.warning(f"{input_tar} does not exist to copy. Skipping ...")
         FileHandler({'copy_opt': diag_tar_copy_list}).sync()
 
         # Untar and gunzip diag files
-        gsi_diag_tars = glob.glob(os.path.join(diag_dir_path, f"{self.task_config.APREFIX}*stat"))
+        gsi_diag_tars = glob.glob(os.path.join(diag_dir_path, f"{self.task_config.APREFIX}*stat.tar"))
         for diag_tar in gsi_diag_tars:
             logger.info(f"Untarring {diag_tar}")
             with tarfile.open(diag_tar, "r") as tar:
@@ -234,12 +237,14 @@ def convert_gsi_diags(self) -> None:
         FileHandler({'copy_opt': copy_ges_diags}).sync()
 
         # Convert GSI diag files to ioda files using gsincdiag2ioda converter scripts
+        logger.info("Converting GSI guess diag files to IODA files")
         gsid.proc_gsi_ncdiag(ObsDir=diag_ioda_dir_ges_path, DiagDir=diag_dir_ges_path)
+        logger.info("Converting GSI analysis diag files to IODA files")
         gsid.proc_gsi_ncdiag(ObsDir=diag_ioda_dir_anl_path, DiagDir=diag_dir_anl_path)
 
         # now we need to combine the two sets of ioda files into one file
         # by adding certain groups from the anl file to the ges file
-        ges_ioda_files = glob.glob(os.path.join(diag_ioda_dir_ges_path, '*nc4'))
+        ges_ioda_files = glob.glob(os.path.join(diag_ioda_dir_ges_path, '*nc'))
         for ges_ioda_file in ges_ioda_files:
             anl_ioda_file = ges_ioda_file.replace('_ges_', '_anl_').replace(diag_ioda_dir_ges_path, diag_ioda_dir_anl_path)
             if os.path.exists(anl_ioda_file):
@@ -250,21 +255,25 @@ def convert_gsi_diags(self) -> None:
                 logger.warning(f"{anl_ioda_file} does not exist to combine with {ges_ioda_file}")
                 logger.warning("Skipping this file ...")
 
+        # now, for conventional data, we need to combine certain obspaces
+        logger.info("Combining conventional GSI IODA files by obspace")
+        conv_obsspaces = ['sondes', 'aircraft', 'sfcship', 'sfc']
+        for obspace in conv_obsspaces:
+            logger.info(f"Combining conventional GSI IODA files for obspace {obspace}")
+            FileList = glob.glob(os.path.join(output_dir_path, f"{obspace}_*_gsi_*.nc"))
+            timestamp = self.task_config.current_cycle.strftime('%Y%m%d%H')
+            combined_outfile = os.path.join(output_dir_path, f"{obspace}_gsi_{timestamp}.nc")
+            gsios.combine_obsspace(FileList, combined_outfile, False)
+
         # Tar up the ioda files
         iodastatzipfile = os.path.join(self.task_config.DATA, 'atmos_gsi', 'atmos_gsi_ioda',
                                        f"{self.task_config.APREFIX}atmos_gsi_analysis.ioda_hofx.tar.gz")
         logger.info(f"Compressing GSI IODA files to {iodastatzipfile}")
         # get list of iodastat files to put in tarball
-        iodastatfiles = glob.glob(os.path.join(output_dir_path, '*nc4'))
+        iodastatfiles = glob.glob(os.path.join(output_dir_path, '*nc'))
         logger.info(f"Gathering {len(iodastatfiles)} GSI IODA files to {iodastatzipfile}")
         with tarfile.open(iodastatzipfile, "w|gz") as archive:
             for targetfile in iodastatfiles:
-                # gzip the file before adding to tar
-                with open(targetfile, 'rb') as f_in:
-                    with gzip.open(f"{targetfile}.gz", 'wb') as f_out:
-                        f_out.writelines(f_in)
-                os.remove(targetfile)
-                targetfile = f"{targetfile}.gz"
                 archive.add(targetfile, arcname=os.path.basename(targetfile))
         logger.info(f"Finished compressing GSI IODA files to {iodastatzipfile}")
         # copy to COMOUT
diff --git a/ush/python/pygfs/task/snow_analysis.py b/ush/python/pygfs/task/snow_analysis.py
index 5109070f2b..9c31421bcd 100644
--- a/ush/python/pygfs/task/snow_analysis.py
+++ b/ush/python/pygfs/task/snow_analysis.py
@@ -48,14 +48,46 @@ def __init__(self, config: Dict[str, Any]):
         super().__init__(config)
 
         _res = int(self.task_config['CASE'][1:])
+        _fail_on_missing = str(self.task_config.fail_on_missing_snowobs[0]).lower() == "true" \
+            if isinstance(self.task_config.fail_on_missing_snowobs, list) \
+            else bool(self.task_config.fail_on_missing_snowobs)
 
         # if 00z, do SCF preprocessing
-        _ims_file = os.path.join(self.task_config.COMIN_OBS, f'{self.task_config.OPREFIX}imssnow96.asc')
+        _ims_file = os.path.join(
+            self.task_config.COMIN_OBS,
+            f'{self.task_config.OPREFIX}imssnow96.{self.task_config.ims_scf_obs_suffix}'
+        )
         logger.info(f"Checking for IMS file: {_ims_file}")
-        if self.task_config.cyc == 0 and os.path.exists(_ims_file):
-            _DO_IMS_SCF = True
+        _DO_IMS_SCF = False
+        if self.task_config.cyc == 0:
+            if os.path.exists(_ims_file):
+                _DO_IMS_SCF = True
+            else:
+                if _fail_on_missing:
+                    raise FileNotFoundError(
+                        f"IMS obs file required but not found: {_ims_file}"
+                    )
+                else:
+                    logger.warning(f"IMS obs file missing: {_ims_file}")
+        else:
+            logger.info("Not 00z cycle — Skipping IMS preprocessing.")
+
+        # if 00z, do GHCN preprocessing
+        _ghcn_file = os.path.join(self.task_config.COMIN_OBS, f'{self.task_config.OPREFIX}ghcn_snow.csv')
+        logger.info(f"Checking for GHCN csv file: {_ghcn_file}")
+        _DO_GHCN = False
+        if self.task_config.cyc == 0:
+            if os.path.exists(_ghcn_file):
+                _DO_GHCN = True
+            else:
+                if _fail_on_missing:
+                    raise FileNotFoundError(
+                        f"GHCN obs file required but not found: {_ghcn_file}"
+                    )
+                else:
+                    logger.warning(f"GHCN obs file missing: {_ghcn_file}")
         else:
-            _DO_IMS_SCF = False
+            logger.info("Not 00z cycle — Skipping GHCN preprocessing.")
 
         # Extend task_config with variables repeatedly used across this class
         self.task_config.update(AttrDict(
@@ -68,6 +100,7 @@ def __init__(self, config: Dict[str, Any]):
                 'snow_prepobs_path': os.path.join(self.task_config.DATA, 'prep'),
                 'ims_file': _ims_file,
                 'DO_IMS_SCF': _DO_IMS_SCF,  # Boolean to decide if IMS snow cover processing is done
+                'DO_GHCN': _DO_GHCN,  # Boolean to decide if GHCN processing is done
             }
         ))
 
@@ -222,6 +255,74 @@ def prepare_SNOCVR_SNOMAD(self) -> None:
             logger.info(f"Copy {output_file} successfully generated")
             FileHandler(prep_snocvr_snomad_config.netcdf).sync()
 
+    @logit(logger)
+    def prepare_GHCN(self) -> None:
+        """Prepare the GHCN data for a global snow analysis
+
+        This method will prepare GHCN data for a global snow analysis using JEDI.
+        This includes:
+        - creating GHCN snowdepth data in IODA format.
+
+        Parameters
+        ----------
+        Analysis: parent class for GDAS task
+
+        Returns
+        ----------
+        None
+        """
+
+        # Read and render the prep_ghcn.yaml.j2
+        logger.info(f"Reading {self.task_config.PREP_GHCN_YAML}")
+        prep_ghcn_config = parse_j2yaml(self.task_config.PREP_GHCN_YAML, self.task_config)
+        logger.debug(f"{self.task_config.PREP_GHCN_YAML}:\n{pformat(prep_ghcn_config)}")
+
+        # Define these locations in gdas/snow/prep/prep_ghcn.yaml.j2
+        logger.info("Copying GHCN obs to DATA")
+        FileHandler(prep_ghcn_config.stage).sync()
+
+        # Execute ioda converter to create the GHCN obs data in IODA format
+        logger.info("Create GHCN obs data in IODA format")
+
+        csv_file = f'{self.task_config.OPREFIX}ghcn_snow.csv'
+        station_file = f'ghcnd-stations.txt'
+        output_file = f'{self.task_config.OPREFIX}ghcn_snow.nc'
+        if os.path.exists(f"{os.path.join(self.task_config.DATA, output_file)}"):
+            rm_p(output_file)
+        if not os.path.isfile(csv_file):
+            logger.warning(f"WARNING: GHCN obs file not found.")
+            return
+
+        logger.info("Link GHCN2IODACONV into DATA/")
+        exe_src = self.task_config.GHCN2IODACONV
+        exe_dest = os.path.join(self.task_config.DATA, os.path.basename(exe_src))
+        if os.path.exists(exe_dest):
+            rm_p(exe_dest)
+        os.symlink(exe_src, exe_dest)
+
+        exe = Executable(exe_dest)
+        exe.add_default_arg(["-i", f"{os.path.join(self.task_config.DATA, csv_file)}"])
+        exe.add_default_arg(["-o", f"{os.path.join(self.task_config.DATA, output_file)}"])
+        exe.add_default_arg(["-f", f"{os.path.join(self.task_config.DATA, station_file)}"])
+        exe.add_default_arg(["-d", f"{to_YMDH(self.task_config.current_cycle)}"])
+        try:
+            logger.debug(f"Executing {exe}")
+            exe()
+        except OSError:
+            logger.exception(f"Failed to execute {exe}")
+            raise
+        except Exception as err:
+            logger.exception(f"An error occured during execution of {exe}")
+            raise WorkflowException(f"An error occured during execution of {exe}") from err
+
+        # Ensure the IODA snow depth GHCN file is produced by the IODA converter
+        # If so, copy to DATA/prep/
+        if not os.path.isfile(f"{os.path.join(self.task_config.DATA, output_file)}"):
+            logger.warning(f"{output_file} not produced - continuing without it.")
+        else:
+            logger.info(f"Copy {output_file} successfully generated")
+            FileHandler(prep_ghcn_config.ghcn2ioda).sync()
+
     @logit(logger)
     def add_increments(self) -> None:
         """Executes the program "apply_incr.exe" to create analysis "sfc_data" files by adding increments to backgrounds
diff --git a/ush/python/pygfs/task/snowens_analysis.py b/ush/python/pygfs/task/snowens_analysis.py
index c876d94f29..5f289aff01 100644
--- a/ush/python/pygfs/task/snowens_analysis.py
+++ b/ush/python/pygfs/task/snowens_analysis.py
@@ -51,14 +51,46 @@ def __init__(self, config: Dict[str, Any]):
         super().__init__(config)
 
         _res = int(self.task_config['CASE_ENS'][1:])
+        _fail_on_missing = str(self.task_config.fail_on_missing_snowobs[0]).lower() == "true" \
+            if isinstance(self.task_config.fail_on_missing_snowobs, list) \
+            else bool(self.task_config.fail_on_missing_snowobs)
 
         # if 00z, do SCF preprocessing
-        _ims_file = os.path.join(self.task_config.COMIN_OBS, f'{self.task_config.OPREFIX}imssnow96.asc')
+        _ims_file = os.path.join(
+            self.task_config.COMIN_OBS,
+            f'{self.task_config.OPREFIX}imssnow96.{self.task_config.ims_scf_obs_suffix}'
+        )
         logger.info(f"Checking for IMS file: {_ims_file}")
-        if self.task_config.cyc == 0 and os.path.exists(_ims_file):
-            _DO_IMS_SCF = True
+        _DO_IMS_SCF = False
+        if self.task_config.cyc == 0:
+            if os.path.exists(_ims_file):
+                _DO_IMS_SCF = True
+            else:
+                if _fail_on_missing:
+                    raise FileNotFoundError(
+                        f"IMS obs file required but not found: {_ims_file}"
+                    )
+                else:
+                    logger.warning(f"IMS obs file missing: {_ims_file}")
+        else:
+            logger.info("Not 00z cycle — Skipping IMS preprocessing.")
+
+        # if 00z, do GHCN preprocessing
+        _ghcn_file = os.path.join(self.task_config.COMIN_OBS, f'{self.task_config.OPREFIX}ghcn_snow.csv')
+        logger.info(f"Checking for GHCN csv file: {_ghcn_file}")
+        _DO_GHCN = False
+        if self.task_config.cyc == 0:
+            if os.path.exists(_ghcn_file):
+                _DO_GHCN = True
+            else:
+                if _fail_on_missing:
+                    raise FileNotFoundError(
+                        f"GHCN obs file required but not found: {_ghcn_file}"
+                    )
+                else:
+                    logger.warning(f"GHCN obs file missing: {_ghcn_file}")
         else:
-            _DO_IMS_SCF = False
+            logger.info("Not 00z cycle — Skipping GHCN preprocessing.")
 
         # Extend task_config with variables repeatedly used across this class
         self.task_config.update(AttrDict(
@@ -69,8 +101,10 @@ def __init__(self, config: Dict[str, Any]):
                 'npz': self.task_config.LEVS - 1,
                 'CASE': self.task_config.CASE_ENS,
                 'snow_bkg_path': os.path.join('.', 'bkg', 'ensmean/'),
+                'snow_prepobs_path': os.path.join(self.task_config.DATA, 'prep'),
                 'ims_file': _ims_file,
                 'DO_IMS_SCF': _DO_IMS_SCF,  # Boolean to decide if IMS snow cover processing is done
+                'DO_GHCN': _DO_GHCN,  # Boolean to decide if GHCN processing is done
             }
         ))
 
@@ -226,6 +260,71 @@ def prepare_SNOCVR_SNOMAD(self) -> None:
             logger.info(f"Copy {output_file} successfully generated")
             FileHandler(prep_snocvr_snomad_config.netcdf).sync()
 
+    @logit(logger)
+    def prepare_GHCN(self) -> None:
+        """Prepare the GHCN data for a global snow analysis
+        This method will prepare GHCN data for a global snow analysis using JEDI.
+        This includes:
+        - creating GHCN snowdepth data in IODA format.
+        Parameters
+        ----------
+        Analysis: parent class for GDAS task
+        Returns
+        ----------
+        None
+        """
+
+        # Read and render the prep_ghcn.yaml.j2
+        logger.info(f"Reading {self.task_config.PREP_GHCN_YAML}")
+        prep_ghcn_config = parse_j2yaml(self.task_config.PREP_GHCN_YAML, self.task_config)
+        logger.debug(f"{self.task_config.PREP_GHCN_YAML}:\n{pformat(prep_ghcn_config)}")
+
+        # Define these locations in gdas/snow/prep/prep_ghcn.yaml.j2
+        logger.info("Copying GHCN obs to DATA")
+        FileHandler(prep_ghcn_config.stage).sync()
+
+        # Execute ioda converter to create the GHCN obs data in IODA format
+        logger.info("Create GHCN obs data in IODA format")
+
+        csv_file = f'{self.task_config.OPREFIX}ghcn_snow.csv'
+        station_file = f'ghcnd-stations.txt'
+        output_file = f'{self.task_config.OPREFIX}ghcn_snow.nc'
+        if os.path.exists(f"{os.path.join(self.task_config.DATA, output_file)}"):
+            rm_p(output_file)
+        if not os.path.isfile(csv_file):
+            logger.warning(f"WARNING: GHCN obs file not found.")
+            return
+
+        logger.info("Link GHCN2IODACONV into DATA/")
+        exe_src = self.task_config.GHCN2IODACONV
+        exe_dest = os.path.join(self.task_config.DATA, os.path.basename(exe_src))
+        if os.path.exists(exe_dest):
+            rm_p(exe_dest)
+        os.symlink(exe_src, exe_dest)
+
+        exe = Executable(exe_dest)
+        exe.add_default_arg(["-i", f"{os.path.join(self.task_config.DATA, csv_file)}"])
+        exe.add_default_arg(["-o", f"{os.path.join(self.task_config.DATA, output_file)}"])
+        exe.add_default_arg(["-f", f"{os.path.join(self.task_config.DATA, station_file)}"])
+        exe.add_default_arg(["-d", f"{to_YMDH(self.task_config.current_cycle)}"])
+        try:
+            logger.debug(f"Executing {exe}")
+            exe()
+        except OSError:
+            logger.exception(f"Failed to execute {exe}")
+            raise
+        except Exception as err:
+            logger.exception(f"An error occured during execution of {exe}")
+            raise WorkflowException(f"An error occured during execution of {exe}") from err
+
+        # Ensure the IODA snow depth GHCN file is produced by the IODA converter
+        # If so, copy to DATA/prep/
+        if not os.path.isfile(f"{os.path.join(self.task_config.DATA, output_file)}"):
+            logger.warning(f"{output_file} not produced - continuing without it.")
+        else:
+            logger.info(f"Copy {output_file} successfully generated")
+            FileHandler(prep_ghcn_config.ghcn2ioda).sync()
+
     @logit(logger)
     def add_increments(self) -> None:
         """Executes the program "apply_incr.exe" to create analysis "sfc_data" files by adding increments to backgrounds