diff --git a/jobs/JREGIONAL_GET_EXTRN_MDL_FILES b/jobs/JREGIONAL_GET_EXTRN_MDL_FILES
index 6b373895e..bfe2d7bce 100755
--- a/jobs/JREGIONAL_GET_EXTRN_MDL_FILES
+++ b/jobs/JREGIONAL_GET_EXTRN_MDL_FILES
@@ -57,7 +57,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_MAKE_GRID b/jobs/JREGIONAL_MAKE_GRID
index 0ff122bad..b4d549012 100755
--- a/jobs/JREGIONAL_MAKE_GRID
+++ b/jobs/JREGIONAL_MAKE_GRID
@@ -125,7 +125,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_MAKE_ICS b/jobs/JREGIONAL_MAKE_ICS
index 01027b4ac..9c5125f41 100755
--- a/jobs/JREGIONAL_MAKE_ICS
+++ b/jobs/JREGIONAL_MAKE_ICS
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_MAKE_LBCS b/jobs/JREGIONAL_MAKE_LBCS
index b46d0e950..bc7afbaf7 100755
--- a/jobs/JREGIONAL_MAKE_LBCS
+++ b/jobs/JREGIONAL_MAKE_LBCS
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_MAKE_OROG b/jobs/JREGIONAL_MAKE_OROG
index e3935037d..50b6c0369 100755
--- a/jobs/JREGIONAL_MAKE_OROG
+++ b/jobs/JREGIONAL_MAKE_OROG
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_MAKE_SFC_CLIMO b/jobs/JREGIONAL_MAKE_SFC_CLIMO
index f2993bbaf..24af27bfa 100755
--- a/jobs/JREGIONAL_MAKE_SFC_CLIMO
+++ b/jobs/JREGIONAL_MAKE_SFC_CLIMO
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_RUN_FCST b/jobs/JREGIONAL_RUN_FCST
index a4806c765..dbd4c80c4 100755
--- a/jobs/JREGIONAL_RUN_FCST
+++ b/jobs/JREGIONAL_RUN_FCST
@@ -37,7 +37,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/jobs/JREGIONAL_RUN_POST b/jobs/JREGIONAL_RUN_POST
index e4e2122e4..71cc9d85e 100755
--- a/jobs/JREGIONAL_RUN_POST
+++ b/jobs/JREGIONAL_RUN_POST
@@ -36,7 +36,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -100,7 +100,7 @@ cd_vrfy "${fhr_dir}"
 #
 #-----------------------------------------------------------------------
 #
-fhr=$( printf "%s" "${fhr}" | sed -n -r -e "s/^([0-9]+)$/\1/p" )
+fhr=$( printf "%s" "${fhr}" | $SED -n -r -e "s/^([0-9]+)$/\1/p" )
 if [ -z "$fhr" ]; then
   print_err_msg_exit "\
 The forecast hour (fhr) must be a non-empty string consisting of only 
diff --git a/scripts/exregional_get_extrn_mdl_files.sh b/scripts/exregional_get_extrn_mdl_files.sh
index 35e8d373b..ac5127eb8 100755
--- a/scripts/exregional_get_extrn_mdl_files.sh
+++ b/scripts/exregional_get_extrn_mdl_files.sh
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -524,7 +524,7 @@ not happen."
 # to the current directory.  Then move the files.
 #
         rel_dir=$( printf "%s" "${extrn_mdl_arcvrel_dir}" | \
-                   sed -r 's%^(\/|\.\/)([^/]*)(.*)%\2\3%' ) 
+                   $SED -r 's%^(\/|\.\/)([^/]*)(.*)%\2\3%' ) 
         mv_vrfy ${rel_dir}/* .
 #
 # Get the first subdirectory in rel_dir, i.e. the subdirectory before the 
@@ -533,7 +533,7 @@ not happen."
 # it.
 #
         subdir_to_remove=$( printf "%s" "${rel_dir}" | \
-                            sed -r 's%^([^/]*)(.*)%\1%' ) 
+                            $SED -r 's%^([^/]*)(.*)%\1%' ) 
         rm_vrfy -rf ./${subdir_to_remove}
 #
 # If extrn_mdl_arcvrel_dir does not start with a "/" (and it is not 
diff --git a/scripts/exregional_make_grid.sh b/scripts/exregional_make_grid.sh
index 895ab9395..70b7616ed 100755
--- a/scripts/exregional_make_grid.sh
+++ b/scripts/exregional_make_grid.sh
@@ -39,7 +39,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -152,6 +152,14 @@ case $MACHINE in
     ulimit -a
     ;;
 
+  "MACOS")
+    APRUN=time
+    ;;
+
+  "LINUX")
+    APRUN=time
+    ;;
+
   *)
     print_err_msg_exit "\
 Run command has not been specified for this machine:
@@ -438,11 +446,19 @@ uniform cubed-sphere grid equivalent resolution returned with nonzero exit
 code:
   exec_fp = \"${exec_fp}\""
 
+# Make sure 'ncdump' is available before we try to use it
+if ! command -v ncdump &> /dev/null
+then
+  print_err_msg_exit "\
+The utility 'ncdump' was not found in the environment. Be sure to add the
+netCDF 'bin/' directory to your PATH."
+fi
+
 # Make the following (reading of res_equiv) a function in another file
 # so that it can be used both here and in the exregional_make_orog.sh
 # script.
 res_equiv=$( ncdump -h "${grid_fp}" | \
-             grep -o ":RES_equiv = [0-9]\+" | grep -o "[0-9]" ) || \
+             grep -o ":RES_equiv = [0-9]\+" | $SED 's/[^0-9]*//g' ) || \
 print_err_msg_exit "\
 Attempt to extract the equivalent global uniform cubed-sphere grid reso-
 lution from the grid file (grid_fp) failed:
diff --git a/scripts/exregional_make_ics.sh b/scripts/exregional_make_ics.sh
index fe54d62bf..ffe63d404 100755
--- a/scripts/exregional_make_ics.sh
+++ b/scripts/exregional_make_ics.sh
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -120,6 +120,21 @@ case "$MACHINE" in
     APRUN="ibrun"
     ;;
 
+  "MACOS")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
+  "LINUX")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
+  *)
+    print_err_msg_exit "\
+Run command has not been specified for this machine:
+  MACHINE = \"$MACHINE\"
+  APRUN = \"$APRUN\""
+    ;;
+
 esac
 #
 #-----------------------------------------------------------------------
diff --git a/scripts/exregional_make_lbcs.sh b/scripts/exregional_make_lbcs.sh
index 8e1bcd577..a9380b18a 100755
--- a/scripts/exregional_make_lbcs.sh
+++ b/scripts/exregional_make_lbcs.sh
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -120,6 +120,21 @@ case "$MACHINE" in
     APRUN="ibrun"
     ;;
 
+  "MACOS")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
+  "LINUX")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
+  *)
+    print_err_msg_exit "\
+Run command has not been specified for this machine:
+  MACHINE = \"$MACHINE\"
+  APRUN = \"$APRUN\""
+    ;;
+
 esac
 #
 #-----------------------------------------------------------------------
@@ -480,7 +495,7 @@ list file has not specified for this external model:
   dd="${EXTRN_MDL_CDATE:6:2}"
   hh="${EXTRN_MDL_CDATE:8:2}"
 
-  cdate_crnt_fhr=$( date --utc --date "${yyyymmdd} ${hh} UTC + ${fhr} hours" "+%Y%m%d%H" )
+  cdate_crnt_fhr=$( $DATE_UTIL --utc --date "${yyyymmdd} ${hh} UTC + ${fhr} hours" "+%Y%m%d%H" )
 #
 # Get the month, day, and hour corresponding to the current forecast time
 # of the the external model.
diff --git a/scripts/exregional_make_orog.sh b/scripts/exregional_make_orog.sh
index 9524fcad1..9ef278add 100755
--- a/scripts/exregional_make_orog.sh
+++ b/scripts/exregional_make_orog.sh
@@ -35,7 +35,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -152,6 +152,14 @@ case $MACHINE in
     export APRUN="time"
     ;;
 
+  "MACOS")
+    APRUN=time
+    ;;
+
+  "LINUX")
+    APRUN=time
+    ;;
+
   *)
     print_err_msg_exit "\
 Run command has not been specified for this machine:
diff --git a/scripts/exregional_make_sfc_climo.sh b/scripts/exregional_make_sfc_climo.sh
index baa42c86c..115d1739a 100755
--- a/scripts/exregional_make_sfc_climo.sh
+++ b/scripts/exregional_make_sfc_climo.sh
@@ -35,7 +35,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -174,6 +174,14 @@ case $MACHINE in
     APRUN="ibrun -np ${nprocs}"
     ;;
 
+  "MACOS")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
+  "LINUX")
+    APRUN=$RUN_CMD_UTILS
+    ;;
+
   *)
     print_err_msg_exit "\
 Run command has not been specified for this machine:
diff --git a/scripts/exregional_run_fcst.sh b/scripts/exregional_run_fcst.sh
index 2f3004130..065b42494 100755
--- a/scripts/exregional_run_fcst.sh
+++ b/scripts/exregional_run_fcst.sh
@@ -35,7 +35,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -148,6 +148,14 @@ case $MACHINE in
     APRUN="ibrun -np ${PE_MEMBER01}"
     ;;
 
+  "MACOS")
+    APRUN=$RUN_CMD_FCST
+    ;;
+
+  "LINUX")
+    APRUN=$RUN_CMD_FCST
+    ;;
+
   *)
     print_err_msg_exit "\
 Run command has not been specified for this machine:
@@ -364,9 +372,9 @@ for (( i=0; i<${num_symlinks}; i++ )); do
 
   mapping="${CYCLEDIR_LINKS_TO_FIXam_FILES_MAPPING[$i]}"
   symlink=$( printf "%s\n" "$mapping" | \
-             sed -n -r -e "s/${regex_search}/\1/p" )
+             $SED -n -r -e "s/${regex_search}/\1/p" )
   target=$( printf "%s\n" "$mapping" | \
-            sed -n -r -e "s/${regex_search}/\2/p" )
+            $SED -n -r -e "s/${regex_search}/\2/p" )
 
   symlink="${run_dir}/$symlink"
   target="$FIXam/$target"
diff --git a/scripts/exregional_run_post.sh b/scripts/exregional_run_post.sh
index e3f22a0ff..808cd8093 100755
--- a/scripts/exregional_run_post.sh
+++ b/scripts/exregional_run_post.sh
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -139,6 +139,14 @@ case $MACHINE in
     APRUN="ibrun -n $nprocs"
     ;;
 
+  "MACOS")
+    APRUN=$RUN_CMD_POST
+    ;;
+
+  "LINUX")
+    APRUN=$RUN_CMD_POST
+    ;;
+
   *)
     print_err_msg_exit "\
 Run command has not been specified for this machine:
@@ -211,7 +219,7 @@ tmmark="tm00"
 dyn_file="${run_dir}/dynf${fhr}.nc"
 phy_file="${run_dir}/phyf${fhr}.nc"
 
-post_time=$( date --utc --date "${yyyymmdd} ${hh} UTC + ${fhr} hours" "+%Y%m%d%H" )
+post_time=$( $DATE_UTIL --utc --date "${yyyymmdd} ${hh} UTC + ${fhr} hours" "+%Y%m%d%H" )
 post_yyyy=${post_time:0:4}
 post_mm=${post_time:4:2}
 post_dd=${post_time:6:2}
@@ -282,8 +290,8 @@ mv_vrfy BGRD3D.GrbF${post_fhr} ${postprd_dir}/${NET}.t${cyc}z.bgrd3df${fhr}.${tm
 # and hh are calculated above, i.e. start_date is just cdate but with a
 # space inserted between the dd and hh.  If so, just use "$yyyymmdd $hh"
 # instead of calling sed.
-start_date=$( echo "${cdate}" | sed 's/\([[:digit:]]\{2\}\)$/ \1/' )
-basetime=$( date +%y%j%H%M -d "${start_date}" )
+start_date=$( echo "${cdate}" | $SED 's/\([[:digit:]]\{2\}\)$/ \1/' )
+basetime=$( $DATE_UTIL +%y%j%H%M -d "${start_date}" )
 ln_vrfy -fs ${postprd_dir}/${NET}.t${cyc}z.bgdawpf${fhr}.${tmmark}.grib2 \
             ${postprd_dir}/BGDAWP_${basetime}f${fhr}00
 ln_vrfy -fs ${postprd_dir}/${NET}.t${cyc}z.bgrd3df${fhr}.${tmmark}.grib2 \
diff --git a/tests/run_experiments.sh b/tests/run_experiments.sh
index e396ec559..a85d780fb 100755
--- a/tests/run_experiments.sh
+++ b/tests/run_experiments.sh
@@ -9,7 +9,12 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+if [[ $(uname -s) == Darwin ]]; then
+  command -v greadlink >/dev/null 2>&1 || { echo >&2 "For Darwin-based operating systems (MacOS), the 'greadlink' utility is required to run the UFS SRW Application. Reference the User's Guide for more information about platform requirements. Aborting."; exit 1; }
+  scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+else
+  scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+fi
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -150,7 +155,7 @@ fi
 #
 #-----------------------------------------------------------------------
 #
-expts_list_fp=$( readlink -f "${expts_file}" )
+expts_list_fp=$( $READLINK -f "${expts_file}" )
 
 if [ ! -f "${expts_list_fp}" ]; then
   print_err_msg_exit "\
@@ -222,20 +227,20 @@ for (( i=0; i<=$((num_lines-1)); i++ )); do
 # all_lines.
 #
   all_lines[$i]=$( printf "%s" "${all_lines[$i]}" | \
-                   sed -r -e "s/^[ ]*//" -e "s/[ ]*$//" )
+                   $SED -r -e "s/^[ ]*//" -e "s/[ ]*$//" )
 #
 # Remove spaces before and after all field separators in the current
 # element of all_lines.  Note that we use the pipe symbol, "|", as the
 # field separator.
 #
   all_lines[$i]=$( printf "%s" "${all_lines[$i]}" | \
-                   sed -r -e "s/[ ]*${field_separator}[ ]*/${field_separator}/g" )
+                   $SED -r -e "s/[ ]*${field_separator}[ ]*/${field_separator}/g" )
 #
 # If the last character of the current line is a field separator, remove
 # it.
 #
   all_lines[$i]=$( printf "%s" "${all_lines[$i]}" | \
-                   sed -r -e "s/${field_separator}$//g" )
+                   $SED -r -e "s/${field_separator}$//g" )
 #
 # If after the processing above the current element of all_lines is not
 # empty, save it as the next element of expts_list.
@@ -286,9 +291,9 @@ Processing experiment \"${expts_list[$i]}\" ..."
 #
   regex_search="^([^${field_separator}]*)(${field_separator}(.*)|)"
   baseline_name=$( printf "%s" "${expts_list[$i]}" | \
-                   sed -r -n -e "s/${regex_search}/\1/p" )
+                   $SED -r -n -e "s/${regex_search}/\1/p" )
   remainder=$( printf "%s" "${expts_list[$i]}" | \
-               sed -r -n -e "s/${regex_search}/\3/p" )
+               $SED -r -n -e "s/${regex_search}/\3/p" )
 #
 # Get the names and corresponding values of the variables that need to
 # be modified in the current baseline to obtain the current experiment.
@@ -304,18 +309,18 @@ Processing experiment \"${expts_list[$i]}\" ..."
 # of remainder back into itself.
 #
     next_field=$( printf "%s" "$remainder" | \
-                  sed -r -e "s/${regex_search}/\1/" )
+                  $SED -r -e "s/${regex_search}/\1/" )
     remainder=$( printf "%s" "$remainder" | \
-                 sed -r -e "s/${regex_search}/\3/" )
+                 $SED -r -e "s/${regex_search}/\3/" )
 #
 # Save the name of the variable in the variable-value pair obtained
 # above in the array modvar_name.  Then save the value in the variable-
 # value pair in the array modvar_value.
 #
     modvar_name[${num_mod_vars}]=$( printf "%s" "${next_field}" | \
-                                    sed -r -e "s/^([^=]*)=(.*)/\1/" )
+                                    $SED -r -e "s/^([^=]*)=(.*)/\1/" )
     modvar_value[${num_mod_vars}]=$( printf "%s" "${next_field}" | \
-                                     sed -r -e "s/^([^=]*)=(\")?([^\"]+*)(\")?/\3/" )
+                                     $SED -r -e "s/^([^=]*)=(\")?([^\"]+*)(\")?/\3/" )
 #
 # Increment the index that keeps track of the number of variables that
 # need to be modified in the current baseline to obtain the current ex-
@@ -417,7 +422,7 @@ Please correct and rerun."
 #
 #-----------------------------------------------------------------------
 #
-  MACHINE="${machine^^}"
+  MACHINE=$(echo_uppercase $machine)
   ACCOUNT="${account}"
 
 # Note that if expt_basedir is a null (or unset) string, ${expt_basedir:+/} 
@@ -679,7 +684,7 @@ COMINgfs=\"${COMINgfs}\""
 #
 # Set STMP and PTMP.
 #
-    nco_basedir=$( readlink -f "$homerrfs/../../nco_dirs" )
+    nco_basedir=$( $READLINK -f "$homerrfs/../../nco_dirs" )
     STMP=${stmp:-"${nco_basedir}/stmp"}
     PTMP=${ptmp:-"${nco_basedir}/ptmp"}
 
@@ -729,7 +734,7 @@ machine (MACHINE):
       fi
     elif [ "${EXTRN_MDL_NAME_ICS}" = "HRRR" ] || \
          [ "${EXTRN_MDL_NAME_ICS}" = "RAP" ]; then
-      EXTRN_MDL_FILES_ICS=( "${EXTRN_MDL_NAME_ICS,,}.out.for_f000" )
+      EXTRN_MDL_FILES_ICS=( "$(echo_lowercase $EXTRN_MDL_NAME_ICS).out.for_f000" )
     fi
 
     EXTRN_MDL_SOURCE_BASEDIR_LBCS="${extrn_mdl_source_basedir}/${EXTRN_MDL_NAME_LBCS}"
@@ -759,7 +764,7 @@ boundary conditions specification interval (LBC_SPEC_INTVL_HRS):
       fi
     elif [ "${EXTRN_MDL_NAME_LBCS}" = "HRRR" ] || \
          [ "${EXTRN_MDL_NAME_LBCS}" = "RAP" ]; then
-      EXTRN_MDL_FILES_LBCS=( "${EXTRN_MDL_FILES_LBCS[@]/#/${EXTRN_MDL_NAME_LBCS,,}.out.for_f}" )
+      EXTRN_MDL_FILES_LBCS=( "${EXTRN_MDL_FILES_LBCS[@]/#/$(echo_lowercase $EXTRN_MDL_NAME_LBCS).out.for_f}" )
     fi
 
     str=${str}"
diff --git a/ush/bash_utils/change_case.sh b/ush/bash_utils/change_case.sh
new file mode 100644
index 000000000..0fe69c853
--- /dev/null
+++ b/ush/bash_utils/change_case.sh
@@ -0,0 +1,241 @@
+#
+#-----------------------------------------------------------------------
+#
+# This file defines functions used to change string to all uppercase or
+# all lowercase
+#
+#-----------------------------------------------------------------------
+#
+
+
+#
+#-----------------------------------------------------------------------
+#
+# Function to echo the given string as an uppercase string
+#
+#-----------------------------------------------------------------------
+#
+function echo_uppercase() {
+#
+#-----------------------------------------------------------------------
+#
+# Save current shell options (in a global array).  Then set new options
+# for this script/function.
+#
+#-----------------------------------------------------------------------
+#
+  { save_shell_opts; set -u +x; } > /dev/null 2>&1
+#
+#-----------------------------------------------------------------------
+#
+# Get the full path to the file in which this script/function is located
+# (scrfunc_fp), the name of that file (scrfunc_fn), and the directory in
+# which the file is located (scrfunc_dir).
+#
+#-----------------------------------------------------------------------
+#
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fn=$( basename "${scrfunc_fp}" )
+  local scrfunc_dir=$( dirname "${scrfunc_fp}" )
+#
+#-----------------------------------------------------------------------
+#
+# Get the name of this function.
+#
+#-----------------------------------------------------------------------
+#
+  local func_name="${FUNCNAME[0]}"
+#
+#-----------------------------------------------------------------------
+#
+# Get information about the script or function that calls this function.
+# Note that caller_name will be set as follows:
+#
+# 1) If the caller is a function, caller_name will be set to the name of
+#    that function.
+# 2) If the caller is a sourced script, caller_name will be set to
+#    "script".  Note that a sourced script cannot be the top level
+#    script since by defintion, it is sourced by another script or func-
+#    tion.
+# 3) If the caller is the top-level script, caller_name will be set to
+#    "main".
+#
+# Thus, if caller_name is set to "script" or "main", the caller is a
+# script, and if it is set to anything else, the caller is a function.
+#
+#-----------------------------------------------------------------------
+#
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[1]}" )
+  local caller_fn=$( basename "${caller_fp}" )
+  local caller_dir=$( dirname "${caller_fp}" )
+  local caller_name="${FUNCNAME[1]}"
+#
+# Get input string
+
+  local input
+
+  if [ "$#" -eq 1 ]; then
+
+    input="$1"
+
+#
+#-----------------------------------------------------------------------
+#
+# If no arguments or more than one, print out a usage message and exit.
+#
+#-----------------------------------------------------------------------
+#
+  else
+
+    print_err_msg_exit "
+Incorrect number of arguments specified:
+
+  Function name:  \"${func_name}\"
+  Number of arguments specified:  $#
+
+Usage:
+
+  ${func_name}  string
+
+where:
+
+  string:
+  This is the string that should be converted to uppercase and echoed.
+"
+
+  fi
+
+# Echo the input string as upperercase
+
+echo $input| tr '[a-z]' '[A-Z]'
+
+#
+#-----------------------------------------------------------------------
+#
+# Restore the shell options saved at the beginning of this script/func-
+# tion.
+#
+#-----------------------------------------------------------------------
+#
+  { restore_shell_opts; } > /dev/null 2>&1
+
+
+}
+
+
+#
+#-----------------------------------------------------------------------
+#
+# Function to echo the given string as a lowercase string
+#
+#-----------------------------------------------------------------------
+#
+function echo_lowercase() {
+#
+#-----------------------------------------------------------------------
+#
+# Save current shell options (in a global array).  Then set new options
+# for this script/function.
+#
+#-----------------------------------------------------------------------
+#
+  { save_shell_opts; set -u +x; } > /dev/null 2>&1
+#
+#-----------------------------------------------------------------------
+#
+# Get the full path to the file in which this script/function is located 
+# (scrfunc_fp), the name of that file (scrfunc_fn), and the directory in
+# which the file is located (scrfunc_dir).
+#
+#-----------------------------------------------------------------------
+#
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fn=$( basename "${scrfunc_fp}" )
+  local scrfunc_dir=$( dirname "${scrfunc_fp}" )
+#
+#-----------------------------------------------------------------------
+#
+# Get the name of this function.
+#
+#-----------------------------------------------------------------------
+#
+  local func_name="${FUNCNAME[0]}"
+#
+#-----------------------------------------------------------------------
+#
+# Get information about the script or function that calls this function.
+# Note that caller_name will be set as follows:
+#
+# 1) If the caller is a function, caller_name will be set to the name of 
+#    that function.
+# 2) If the caller is a sourced script, caller_name will be set to 
+#    "script".  Note that a sourced script cannot be the top level 
+#    script since by defintion, it is sourced by another script or func-
+#    tion.
+# 3) If the caller is the top-level script, caller_name will be set to
+#    "main".
+#
+# Thus, if caller_name is set to "script" or "main", the caller is a 
+# script, and if it is set to anything else, the caller is a function.
+#
+#-----------------------------------------------------------------------
+#
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[1]}" )
+  local caller_fn=$( basename "${caller_fp}" )
+  local caller_dir=$( dirname "${caller_fp}" )
+  local caller_name="${FUNCNAME[1]}"
+#
+# Get input string
+
+  local input
+
+  if [ "$#" -eq 1 ]; then
+
+    input="$1"
+    
+#
+#-----------------------------------------------------------------------
+#
+# If no arguments or more than one, print out a usage message and exit.
+#
+#-----------------------------------------------------------------------
+#
+  else
+
+    print_err_msg_exit "
+Incorrect number of arguments specified:
+
+  Function name:  \"${func_name}\"
+  Number of arguments specified:  $#
+
+Usage:
+
+  ${func_name}  string
+
+where:
+
+  string:
+  This is the string that should be converted to lowercase and echoed.
+"
+
+  fi
+
+# Echo the input string as lowercase
+
+echo $input| tr '[A-Z]' '[a-z]'
+
+#
+#-----------------------------------------------------------------------
+#
+# Restore the shell options saved at the beginning of this script/func-
+# tion.
+#
+#-----------------------------------------------------------------------
+#
+  { restore_shell_opts; } > /dev/null 2>&1
+
+
+}
+
+
+
diff --git a/ush/bash_utils/check_for_preexist_dir_file.sh b/ush/bash_utils/check_for_preexist_dir_file.sh
index 7b9b59772..dac2688a3 100644
--- a/ush/bash_utils/check_for_preexist_dir_file.sh
+++ b/ush/bash_utils/check_for_preexist_dir_file.sh
@@ -26,7 +26,7 @@ function check_for_preexist_dir_file() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/check_var_valid_value.sh b/ush/bash_utils/check_var_valid_value.sh
index 723460ea1..7a0e20707 100644
--- a/ush/bash_utils/check_var_valid_value.sh
+++ b/ush/bash_utils/check_var_valid_value.sh
@@ -25,7 +25,7 @@ function check_var_valid_value() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/count_files.sh b/ush/bash_utils/count_files.sh
index 633bbf7ce..c80f342cb 100644
--- a/ush/bash_utils/count_files.sh
+++ b/ush/bash_utils/count_files.sh
@@ -25,7 +25,7 @@ function count_files() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/define_macos_utilities.sh b/ush/bash_utils/define_macos_utilities.sh
new file mode 100644
index 000000000..1c5aca621
--- /dev/null
+++ b/ush/bash_utils/define_macos_utilities.sh
@@ -0,0 +1,45 @@
+#
+#-----------------------------------------------------------------------
+#
+# This script defines MacOS-specific UNIX command-line utilities that 
+# mimic the functionality of the GNU equivalents.
+#
+#-----------------------------------------------------------------------
+#
+#
+#
+#-----------------------------------------------------------------------
+#
+# Check if we are on a Darwin machine; if so we need to use the gnu-like
+# equivalent of readlink and sed.
+#
+#-----------------------------------------------------------------------
+#
+darwinerror () {
+
+  utility=$1
+  echo >&2 "
+For Darwin-based operating systems (MacOS), the '${utility}' utility is required to run the UFS SRW Application.
+Reference the User's Guide for more information about platform requirements.
+
+Aborting.
+"
+  exit 1
+}
+
+  if [[ $(uname -s) == Darwin ]]; then
+    export READLINK=greadlink
+    command -v $READLINK >/dev/null 2>&1 || darwinerror $READLINK
+    export SED=gsed
+    command -v $SED >/dev/null 2>&1 || darwinerror $SED
+    export DATE_UTIL=gdate
+    command -v $DATE_UTIL >/dev/null 2>&1 || darwinerror $DATE_UTIL
+    export LN_UTIL=gln
+    command -v $LN_UTIL >/dev/null 2>&1 || darwinerror $LN_UTIL
+  else
+    export READLINK=readlink
+    export SED=sed
+    export DATE_UTIL=date
+    export LN_UTIL=ln
+  fi
+
diff --git a/ush/bash_utils/filesys_cmds_vrfy.sh b/ush/bash_utils/filesys_cmds_vrfy.sh
index d11ec4720..fc2afe81c 100644
--- a/ush/bash_utils/filesys_cmds_vrfy.sh
+++ b/ush/bash_utils/filesys_cmds_vrfy.sh
@@ -28,7 +28,7 @@ function filesys_cmd_vrfy() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -66,7 +66,7 @@ function filesys_cmd_vrfy() {
 #
 #-----------------------------------------------------------------------
 #
-  local caller_fp=$( readlink -f "${BASH_SOURCE[2]}" )
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[2]}" )
   local caller_fn=$( basename "${caller_fp}" )
   local caller_dir=$( dirname "${caller_fp}" )
   local caller_name="${FUNCNAME[2]}"
@@ -248,7 +248,7 @@ function rm_vrfy() {
 
 function ln_vrfy() {
   { save_shell_opts; set -u +x; } > /dev/null 2>&1
-  filesys_cmd_vrfy "ln" "$@"
+  filesys_cmd_vrfy "$LN_UTIL" "$@"
   { restore_shell_opts; } > /dev/null 2>&1
 }
 
diff --git a/ush/bash_utils/get_charvar_from_netcdf.sh b/ush/bash_utils/get_charvar_from_netcdf.sh
index 71bcf9dd0..ac70cf68d 100644
--- a/ush/bash_utils/get_charvar_from_netcdf.sh
+++ b/ush/bash_utils/get_charvar_from_netcdf.sh
@@ -35,7 +35,7 @@ function get_charvar_from_netcdf() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -173,7 +173,7 @@ The arguments to this function are defined as follows:
 #-----------------------------------------------------------------------
 #
   nc_var_value=$( ncdump -v "${nc_var_name}" "${nc_file}" | \
-                  sed -r -e '1,/data:/d' \
+                  $SED -r -e '1,/data:/d' \
                          -e '/^[ ]*'${nc_var_name}'/d' \
                          -e '/^}$/d' \
                          -e 's/.*"(.*)".*/\1/' \
diff --git a/ush/bash_utils/get_elem_inds.sh b/ush/bash_utils/get_elem_inds.sh
index 70da5b248..89a9c4122 100644
--- a/ush/bash_utils/get_elem_inds.sh
+++ b/ush/bash_utils/get_elem_inds.sh
@@ -24,7 +24,7 @@ function get_elem_inds() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -123,7 +123,7 @@ The arguments to this function are defined as follows:
 #
 #-----------------------------------------------------------------------
 #
-  inds_to_return="${inds_to_return,,}"
+  inds_to_return=$(echo_lowercase $inds_to_return)
   valid_vals_inds_to_return=( "first" "last" "all" )
   check_var_valid_value "inds_to_return" "valid_vals_inds_to_return"
 #
diff --git a/ush/bash_utils/get_manage_externals_config_property.sh b/ush/bash_utils/get_manage_externals_config_property.sh
index b42605ec9..370d448f2 100644
--- a/ush/bash_utils/get_manage_externals_config_property.sh
+++ b/ush/bash_utils/get_manage_externals_config_property.sh
@@ -24,7 +24,7 @@ function get_manage_externals_config_property() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -184,7 +184,7 @@ does not exist:
 #-----------------------------------------------------------------------
 #
   regex_search="^[ ]*(${property_name})[ ]*=[ ]*([^ ]*).*"
-  line=$( sed -r -n \
+  line=$( $SED -r -n \
               -e "/^[ ]*\[${external_name}\]/!b" \
               -e ":SearchForLine" \
               -e "s/(${regex_search})/\1/;t FoundLine" \
@@ -225,7 +225,7 @@ fied external (external_name):
   else
 
     property_value=$( printf "%s" "${line}" | \
-                      sed -r -n -e "s/${regex_search}/\2/p" )
+                      $SED -r -n -e "s/${regex_search}/\2/p" )
     printf "%s\n" "${property_value}"
 
   fi
diff --git a/ush/bash_utils/interpol_to_arbit_CRES.sh b/ush/bash_utils/interpol_to_arbit_CRES.sh
index 6f685c1a5..bc4c6e833 100644
--- a/ush/bash_utils/interpol_to_arbit_CRES.sh
+++ b/ush/bash_utils/interpol_to_arbit_CRES.sh
@@ -27,7 +27,7 @@ function interpol_to_arbit_CRES() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/is_array.sh b/ush/bash_utils/is_array.sh
index 16be2fbb7..c831f313e 100644
--- a/ush/bash_utils/is_array.sh
+++ b/ush/bash_utils/is_array.sh
@@ -31,7 +31,7 @@ function is_array() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/is_element_of.sh b/ush/bash_utils/is_element_of.sh
index bd92c6f3f..e5a421dab 100644
--- a/ush/bash_utils/is_element_of.sh
+++ b/ush/bash_utils/is_element_of.sh
@@ -24,7 +24,7 @@ function is_element_of() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/bash_utils/print_input_args.sh b/ush/bash_utils/print_input_args.sh
index 10bbe4ca6..72b7744b3 100644
--- a/ush/bash_utils/print_input_args.sh
+++ b/ush/bash_utils/print_input_args.sh
@@ -31,7 +31,7 @@ function print_input_args() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -62,7 +62,7 @@ function print_input_args() {
 #
 #-----------------------------------------------------------------------
 #
-  local caller_fp=$( readlink -f "${BASH_SOURCE[1]}" )
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[1]}" )
   local caller_fn=$( basename "${caller_fp}" )
   local caller_dir=$( dirname "${caller_fp}" )
   local caller_name="${FUNCNAME[1]}"
@@ -174,7 +174,7 @@ have been set as follows:
 #
 #-----------------------------------------------------------------------
 #
-  if [ ! -v VERBOSE ]; then
+  if [ -z ${VERBOSE+x} ]; then
     print_info_msg "$msg"
   else
     print_info_msg "$VERBOSE" "$msg"
diff --git a/ush/bash_utils/print_msg.sh b/ush/bash_utils/print_msg.sh
index 544357f62..d83732942 100644
--- a/ush/bash_utils/print_msg.sh
+++ b/ush/bash_utils/print_msg.sh
@@ -33,7 +33,7 @@ function print_info_msg() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -64,7 +64,7 @@ function print_info_msg() {
 #
 #-----------------------------------------------------------------------
 #
-  local caller_fp=$( readlink -f "${BASH_SOURCE[1]}" )
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[1]}" )
   local caller_fn=$( basename "${caller_fp}" )
   local caller_dir=$( dirname "${caller_fp}" )
   local caller_name="${FUNCNAME[1]}"
@@ -182,7 +182,7 @@ function print_err_msg_exit() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -213,7 +213,7 @@ function print_err_msg_exit() {
 #
 #-----------------------------------------------------------------------
 #
-  local caller_fp=$( readlink -f "${BASH_SOURCE[1]}" )
+  local caller_fp=$( $READLINK -f "${BASH_SOURCE[1]}" )
   local caller_fn=$( basename "${caller_fp}" )
   local caller_dir=$( dirname "${caller_fp}" )
   local caller_name="${FUNCNAME[1]}"
diff --git a/ush/bash_utils/process_args.sh b/ush/bash_utils/process_args.sh
index 4363348ba..203bdedcf 100644
--- a/ush/bash_utils/process_args.sh
+++ b/ush/bash_utils/process_args.sh
@@ -99,7 +99,7 @@ function process_args() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -263,7 +263,7 @@ ments (num_valid_args) specified in the array valid_arg_names:
 
 # Remove spaces (if any exist) from the current valid argument name.
     valid_arg_name_no_spaces=$( \
-      printf "%s\n" "${valid_arg_name}" | sed -r -e 's/[[:space:]]//g' )
+      printf "%s\n" "${valid_arg_name}" | $SED -r -e 's/[[:space:]]//g' )
 
     if [ "${valid_arg_name_no_spaces}" != "${valid_arg_name}" ]; then
       print_err_msg_exit "\
diff --git a/ush/bash_utils/save_restore_shell_opts.sh b/ush/bash_utils/save_restore_shell_opts.sh
index 37f699590..b561b6cea 100644
--- a/ush/bash_utils/save_restore_shell_opts.sh
+++ b/ush/bash_utils/save_restore_shell_opts.sh
@@ -19,7 +19,7 @@ function save_shell_opts() {
 #
   local shell_opts="$(set +o)"$'\n'"set -$-"
   shell_opts=${shell_opts//$'\n'/ }
-  shell_opts=$( printf "%s\n" "$shell_opts" | sed -r -e "s/set ([+-])/\1/g" )
+  shell_opts=$( printf "%s\n" "$shell_opts" | $SED -r -e "s/set ([+-])/\1/g" )
 #
 # Store the current set of shell options in the global array shell_-
 # opts_array so we can reuse them later.
diff --git a/ush/bash_utils/set_bash_param.sh b/ush/bash_utils/set_bash_param.sh
index 12c2e49be..dd2220607 100644
--- a/ush/bash_utils/set_bash_param.sh
+++ b/ush/bash_utils/set_bash_param.sh
@@ -25,7 +25,7 @@ function set_bash_param() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -129,7 +129,7 @@ lar expression (regex_search):
   regex_search = ${regex_search}"
     }; 
 
-  sed -i -r -e "s%${regex_search}%${regex_replace}%" "${file_full_path}"
+  $SED -i -r -e "s%${regex_search}%${regex_replace}%" "${file_full_path}"
 #
 #-----------------------------------------------------------------------
 #
diff --git a/ush/bash_utils/set_file_param.sh b/ush/bash_utils/set_file_param.sh
index 72a9ab041..d45451483 100644
--- a/ush/bash_utils/set_file_param.sh
+++ b/ush/bash_utils/set_file_param.sh
@@ -25,7 +25,7 @@ function set_file_param() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -171,7 +171,7 @@ specified for this file:
   grep -q -E "${regex_search}" "${file_full_path}"
 
   if [ $? -eq 0 ]; then
-    sed -i -r -e "s%${regex_search}%${regex_replace}%" "${file_full_path}"
+    $SED -i -r -e "s%${regex_search}%${regex_replace}%" "${file_full_path}"
   else
     print_err_msg_exit "\
 Specified file (file_full_path) does not contain the searched-for regu-
diff --git a/ush/cmp_expt_to_baseline.sh b/ush/cmp_expt_to_baseline.sh
deleted file mode 100755
index 94e6e0c47..000000000
--- a/ush/cmp_expt_to_baseline.sh
+++ /dev/null
@@ -1,411 +0,0 @@
-#!/bin/sh -l
-#-----------------------------------------------------------------------
-#  Description:  Compare experiment to a baseline.  Can be run with one
-#                or two command line arguments.  With one argument, it
-#                assumes this is your experiment directory and creates a
-#                directory for the baseline based on your experiment's
-#                setup (by reading in the var_defns.sh file in your ex-
-#                periment directory).  With two arguments, it takes the
-#                first one to be your experiment directory and the second
-#                the baseline directory.
-#
-#  Usage: ./cmp_expt_to_baseline.sh ${expt_dir} [${baseline_dir}]
-#
-#  Assumptions:  RUNDIR1 and RUNDIR2 have the same subdirectory structure.
-#                nccmp is available as module load
-#                Script has only been tested on theia
-#-----------------------------------------------------------------------
-
-# Do these need to be machine specific, e.g. by using modulefiles?
-module load intel
-module load nccmp
-#
-#-----------------------------------------------------------------------
-#
-# Get the full path to the file in which this script/function is located 
-# (scrfunc_fp), the name of that file (scrfunc_fn), and the directory in
-# which the file is located (scrfunc_dir).
-#
-#-----------------------------------------------------------------------
-#
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
-scrfunc_fn=$( basename "${scrfunc_fp}" )
-scrfunc_dir=$( dirname "${scrfunc_fp}" )
-#
-#-----------------------------------------------------------------------
-#
-# Source bash utility functions.
-#
-#-----------------------------------------------------------------------
-#
-. ${scrfunc_dir}/source_util_funcs.sh
-#
-#-----------------------------------------------------------------------
-#
-# Save current shell options (in a global array).  Then set new options
-# for this script/function.
-#
-#-----------------------------------------------------------------------
-#
-{ save_shell_opts; set -u +x; } > /dev/null 2>&1
-#
-#-----------------------------------------------------------------------
-#
-# Process arguments.
-#
-#-----------------------------------------------------------------------
-#
-if [ $# -eq 0 ] || [ $# -gt 2 ]; then
-
-  printf "
-ERROR from script ${scrfunc_fn}:
-Only 1 or 2 arguments may be specified.  Usage:
-
-  > ${scrfunc_fn}  expt_dir  [baseline_dir]
-
-where expt_dir is the experiment directory and baseline_dir is an op-
-tional baseline directory.
-Exiting with nonzero exit code.
-"
-  exit 1
-
-fi
-#
-#-----------------------------------------------------------------------
-#
-# Set the experiment directory and make sure that it exists.
-#
-#-----------------------------------------------------------------------
-#
-expt_dir="$1"
-if [ ! -d "${expt_dir}" ]; then
-  print_err_msg_exit "\
-The specified experiment directory (expt_dir) does not exist:
-  expt_dir = \"$expt_dir\"
-Exiting script with nonzero return code."
-fi
-#
-#-----------------------------------------------------------------------
-#
-# Read the variable definitions file in the experiment directory.
-#
-#-----------------------------------------------------------------------
-#
-. ${expt_dir}/var_defns.sh
-CDATE="${DATE_FIRST_CYCL[0]}${CYCL_HRS[0]}"
-#
-#-----------------------------------------------------------------------
-#
-# If two arguments are specified, then take the second one to be the di-
-# rectory for the baseline.  If only one argument is specified, form a
-# baseline directory name from the parameters used in the experiment di-
-# rectory.  If any other number of arguments is specified, print out an
-# error message and exit.
-#
-#-----------------------------------------------------------------------
-#
-if [ $# -eq 2 ]; then
-
-  baseline_dir="$2"
-
-else
-
-  baseline_dir="/scratch2/BMC/det/regional_FV3/regr_baselines"
-  if [ -n ${PREDEF_GRID_NAME} ]; then
-    baseline_dir="${baseline_dir}/${PREDEF_GRID_NAME}"
-  else
-    printf "\
-The experiment must be run on one of the predefined domains.  Thus, 
-PREDEF_GRID_NAME cannot be empty:
-  PREDEF_GRID_NAME = \"${PREDEF_GRID_NAME}\"
-Exiting script with nonzero return code.
-"
-    exit 1
-  fi
-  baseline_dir="${baseline_dir}/${CCPP_PHYS_SUITE}phys"
-  baseline_dir="${baseline_dir}/ICs-${EXTRN_MDL_NAME_ICS}_LBCs-${EXTRN_MDL_NAME_LBCS}"
-  baseline_dir="${baseline_dir}/$CDATE"
-
-fi
-#
-# Make sure that the baseline directory exists.
-#
-if [ ! -d "${baseline_dir}" ]; then
-  printf "\n
-A baseline directory corresponding to the configuration used in the ex-
-periment directory (expt_dir) does not exist:
-  expt_dir = \"$expt_dir\"
-  baseline_dir (missing) = \"$baseline_dir\"
-Exiting script with nonzero return code."
-  exit 1
-fi
-#
-#-----------------------------------------------------------------------
-#
-# Print out the experiment and baseline directories.
-#
-#-----------------------------------------------------------------------
-#
-print_info_msg "
-The experiment and baseline directories are:
-  expt_dir = \"$expt_dir\"
-  baseline_dir = \"$baseline_dir\""
-#
-#-----------------------------------------------------------------------
-#
-# Set the array containing the names of the subdirectories that will be
-# compared.
-#
-#-----------------------------------------------------------------------
-#
-# This list should also include $CDATE/postprd since that contains the 
-# post-processed grib files, but those files' names don't end in a 
-# standard file extension, e.g. .grb, etc.  Must look into this more.
-#          "grid" \
-#          "orog" \
-#          "sfc_climo" \
-subdirs=( "." \
-          "fix_lam" \
-          "$CDATE/${EXTRN_MDL_NAME_ICS}/ICS" \
-          "$CDATE/${EXTRN_MDL_NAME_LBCS}/LBCS" \
-          "$CDATE/INPUT" \
-          "$CDATE/RESTART" \
-          "$CDATE" \
-          )
-#
-#-----------------------------------------------------------------------
-#
-# Set the array that defines the file extensions to compare in each sub-
-# directory.
-#
-#-----------------------------------------------------------------------
-#
-#declare -a file_extensions=( "nc" "nemsio" "grb" )
-declare -a file_extensions=( "nc" "grb" )
-#declare -a file_extensions=( "nc" )
-#
-#-----------------------------------------------------------------------
-# 
-# Initialize file counts to 0.  These are defined as follows:
-# 
-# nfiles_total:
-# The number of files in the experiment directory that we attempted to 
-# compare to the corresponding file in the baseline directory.
-# 
-# nfiles_missing:
-# The number of files (out of nfiles_total) that are missing from the
-# baseline directory.
-#
-# nfiles_different:
-# The number of files that exist in both the experiment and baseline di-
-# rectories and are different.
-#
-#-----------------------------------------------------------------------
-#
-nfiles_total=0
-nfiles_missing=0
-nfiles_different=0
-#
-#-----------------------------------------------------------------------
-#
-# Loop over the specified subdirectories.  For each subdirectory, com-
-# pare files having the specified extensions for the experiment and the
-# baseline.
-#
-#-----------------------------------------------------------------------
-#
-for subdir in "${subdirs[@]}"; do
-
-  msg="Comparing files in subdirectory \"$subdir\" ..."
-  msglen=${#msg}
-  printf "\n%s\n" "$msg"
-  printf "%0.s=" $(seq 1 $msglen)
-  printf "\n"
-
-  for file_ext in "${file_extensions[@]}"; do
-
-    msg="Comparing files with extension \"${file_ext}\" ..."
-    msglen=${#msg}
-    printf "\n%s\n" "  $msg"
-    printf "  "
-    printf "%0.s~" $(seq 1 $msglen)
-    printf "\n"
-
-#    cmp_files_btwn_dirs "$expt_dir/$subdir" "${baseline_dir}/$subdir" "${ext}" || { \
-#    printf "
-#Call to file comparison function failed.  Exiting with nonzero exit code.
-#"; 
-#    exit 1; }
-#
-#-----------------------------------------------------------------------
-#
-#
-#-----------------------------------------------------------------------
-#
-    if [ "$file_ext" = "nemsio" ] || [ "$file_ext" = "grb" ]; then
-      compare_tool="cmp"
-    elif [ "$file_ext" = "nc" ]; then
-      compare_tool="nccmp -d"
-    else
-      printf "\
-The file comparison tool to use for this file extension has not been 
-specified:
-  file_ext = \"${file_ext}\"
-Please specify the compare tool and rerun.
-Exiting script with nonzero exit code.
-"
-    fi
-#
-#-----------------------------------------------------------------------
-#
-#
-#
-#-----------------------------------------------------------------------
-#
-    cd ${expt_dir}/$subdir
-    num_files=$( ls -1 *.${file_ext} 2>/dev/null | wc -l )
-#   num_files=$( count_files *.${file_ext} 2>/dev/null | wc -l )
-    printf "
-    Number of files with extension \"${file_ext}\" in subdirectory \"$subdir\" 
-    of the experiment directory is:  ${num_files}
-"
-
-    if [ "${num_files}" -eq "0" ]; then
-      printf "\
-    Skipping comparison of files with extension \"${file_ext}\" in this subdirectory.
-"
-    else
-
-      fn_len_max=0
-      for fn in *.${file_ext}; do
-        fn_len=${#fn}
-        if [ ${fn_len} -gt ${fn_len_max} ]; then
-          fn_len_max=${fn_len}
-        fi
-      done
-      compare_msg_pre="      Comparing file "
-      msg_len_max=$(( fn_len_max + ${#compare_msg_pre} ))
-  
-      for fn in *.${file_ext}; do
-  
-        nfiles_total=$(( $nfiles_total + 1 ))
-  
-        fn1="$fn" 
-        fn2="${baseline_dir}/$subdir/$fn"
-        if [ ! -e "$fn2" ]; then  # Check if file exists in baseline directory.
-  
-          printf "
-        File specified by fn exists in subdirectory \"$subdir\" of the
-        experiment directory but not in that of the the baseline directory:
-          fn = \"$fn\"
-          subdir = \"$subdir\"
-        Incrementing missing file count and moving to next file or sub-
-        directory.\n"
-          nfiles_missing=$(( nfiles_missing + 1 ))
-  
-        else
-  
-          msg="${compare_msg_pre}\"$fn\""
-          msg_len="${#msg}"
-          num_dots=$(( msg_len_max - msg_len + 7 ))
-          dots_str=$( printf "%0.s." $(seq 1 ${num_dots} ) )
-          msg="${msg} ${dots_str}"
-  
-          printf "$msg"
-          eval_output=$( eval ${compare_tool} $fn1 $fn2 2>&1 ) 
-  
-          if [ $? -eq 0 ]; then
-            printf " Files are identical.\n"
-          else
-            printf " FILES ARE DIFFERENT!!!\n"
-            printf "\
-        Error message from \"${compare_tool}\" command is:
-${eval_output}
-"
-            nfiles_different=$(( $nfiles_different + 1 ))
-          fi
-    
-        fi
-  
-      done # Loop over files of the same extension.
-
-    fi # Number of files > 0
-
-  done # Loop over file extensions.
-
-done # Loop over subdirectories.
-#
-#-----------------------------------------------------------------------
-#
-# Print out final results.
-#
-#-----------------------------------------------------------------------
-#
-msg="Summary of regression test:"
-msglen=${#msg}
-msg="$msg"
-printf "\n%s\n" "$msg"
-printf "%0.s=" $(seq 1 $msglen)
-printf "\n"
-
-file_extensions_str=$(printf "\"%s\" " "${file_extensions[@]}");
-file_extensions_str="( ${file_extensions_str})"
-
-printf "
-  expt_dir = \"$expt_dir\"
-  baseline_dir = \"$baseline_dir\"
-
-  file_extensions = ${file_extensions_str}
-  nfiles_total = ${nfiles_total}
-  nfiles_missing = ${nfiles_missing}
-  nfiles_different = ${nfiles_different}
-
-where
-
-  file_extensions:
-  Array containing the file extensions considered when comparing files.  
-  Only files ending with one of these extensions are compared.
-
-  nfiles_total:
-  The number of files in the experiment directory that we attempted to 
-  compare to the corresponding file in the baseline directory.
-
-  nfiles_missing:
-  The number of files (out of nfiles_total) that are missing from the
-  baseline directory.
-
-  nfiles_different:
-  The number of files that exist in both the experiment and baseline di-
-  rectories and are different.
-
-"
-
-if [ ${nfiles_missing} -eq 0 ] && [ ${nfiles_different} -eq 0 ]; then
-  result_str="PASS :)"
-  exit_code=0
-else
-
-  exit_code=1
-  if [ ${nfiles_missing} -ne 0 ] && [ ${nfiles_different} -eq 0 ]; then
-    result_str="FAIL (due to missing files)"
-  elif [ ${nfiles_missing} -eq 0 ] && [ ${nfiles_different} -ne 0 ]; then
-    result_str="FAIL (due to differing files)"
-  elif [ ${nfiles_missing} -ne 0 ] && [ ${nfiles_different} -ne 0 ]; then
-    result_str="FAIL (due to missing and differing files)"
-  fi
-
-fi
-
-printf "Final result of regression test:  ${result_str}\n"
-#
-#-----------------------------------------------------------------------
-#
-# Restore the shell options saved at the beginning of this script/func-
-# tion.
-#
-#-----------------------------------------------------------------------
-#
-{ restore_shell_opts; } > /dev/null 2>&1
-
-exit ${exit_code}
-
diff --git a/ush/cmp_rundirs_ncfiles.sh b/ush/cmp_rundirs_ncfiles.sh
deleted file mode 100755
index c65045487..000000000
--- a/ush/cmp_rundirs_ncfiles.sh
+++ /dev/null
@@ -1,100 +0,0 @@
-#!/bin/sh -l
-
-module load nccmp
-#
-#-----------------------------------------------------------------------
-#
-# Define generic function to compare NetCDF files in two directories.
-#
-#-----------------------------------------------------------------------
-#
-function cmp_ncfiles_one_dir() {
-
-  local dir1="$1"
-  local dir2="$2"
-  local subdir="$3"
-  local fileext="$4"
-  
-  local fn=""
-  local msg=""
-
-  cd $dir1/$subdir
-
-  for fn in *.$fileext; do
- 
-    fn1="$fn" 
-    if [ -f "$fn1" ] && [ ! -L "$fn1" ]; then  # Check if regular file and not a symlink.
-
-      fn2="$dir2/$subdir/$fn"
-      if [ -e "$fn2" ]; then  # Check if file exists.
-
-        if [ -f "$fn2" ] && [ ! -L "$fn2" ]; then  # Check if regular file and not a symlink.
-  
-          printf "\nComparing file \"$fn\" in subdirectory \"$subdir\" ...\n"
-          nccmp -d $fn1 $fn2
-#          nccmp -dS $fn1 $fn2
-#          nccmp -d -t 1e-3 $fn1 $fn2
-#          nccmp -d --precision='%g10.5' $fn1 $fn2
-  
-          if [ $? = 0 ]; then
-            msg=$( printf "%s" "Files are identical." )
-          elif [ $? = 1 ]; then
-            msg=$( printf "%s" "===>>> FILES ARE DIFFERENT!!!" )
-          else
-            msg=$( printf "%s" "FATAL ERROR.  Exiting script." )
-            exit 1
-          fi
-    
-          printf "%s\n" "$msg"
-  
-        else
-          printf "\n%s\n" "File \"$fn\" in \"$dir2/$subdir\" is a symbolic link.  Skipping."
-        fi
-
-      else
-        printf "\n%s\n" "File \"$fn\" does not exist in \"$dir2/$subdir\"."
-        printf "\n%s\n" "Exiting script."
-        exit 1
-      fi
-        
-    else
-      printf "\n%s\n" "File \"$fn\" in \"$dir1/$subdir\" is a symbolic link.  Skipping."
-    fi
-  
-  done
-
-}
-#
-#-----------------------------------------------------------------------
-#
-# Get the two run directories to compare from command-line arguments.  
-# Then compare NetCDF files in the run directories as well as in their
-# INPUT subdirectories.
-#
-#-----------------------------------------------------------------------
-#
-#set -x
-
-rundir1="$( readlink -f $1 )"
-rundir2="$( readlink -f $2 )"
-
-printf "\n"
-printf "%s\n" "rundir1 = \"$rundir1\""
-printf "%s\n" "rundir2 = \"$rundir2\""
-
-subdirs=("INPUT" ".")
-
-for subdir in "${subdirs[@]}"; do
-
-  msg=$( printf "%s" "Comparing files in subdirectory \"$subdir\" ..." )
-  msglen=${#msg}
-  printf "\n%s\n" "$msg"
-  printf "%0.s=" $(seq 1 $msglen)
-  printf "\n"
-
-  cmp_ncfiles_one_dir "$rundir1" "$rundir2" "$subdir" "nc"
-
-done
-
-
-
diff --git a/ush/compare_config_scripts.sh b/ush/compare_config_scripts.sh
index 279903ab3..791fa4e34 100644
--- a/ush/compare_config_scripts.sh
+++ b/ush/compare_config_scripts.sh
@@ -19,7 +19,7 @@ function compare_config_scripts() {
 #
 #-----------------------------------------------------------------------
 #
-local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 local scrfunc_fn=$( basename "${scrfunc_fp}" )
 local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -65,7 +65,7 @@ local func_name="${FUNCNAME[0]}"
 #-----------------------------------------------------------------------
 #
 var_list_default=$( \
-sed -r \
+$SED -r \
     -e "s/^([ ]*)([^ ]+.*)/\2/g" \
     -e "/^#.*/d" \
     -e "/^$/d" \
@@ -73,7 +73,7 @@ sed -r \
 )
 
 var_list_local=$( \
-sed -r \
+$SED -r \
     -e "s/^([ ]*)([^ ]+.*)/\2/g" \
     -e "/^#.*/d" \
     -e "/^$/d" \
@@ -95,7 +95,7 @@ while read crnt_line; do
 # Note that a variable name will be found only if the equal sign immed-
 # iately follows the variable name.
 # 
-  var_name=$( printf "%s" "${crnt_line}" | sed -n -r -e "s/^([^ =\"]*)=.*/\1/p")
+  var_name=$( printf "%s" "${crnt_line}" | $SED -n -r -e "s/^([^ =\"]*)=.*/\1/p")
 
   if [ -z "${var_name}" ]; then
 
diff --git a/ush/config_defaults.sh b/ush/config_defaults.sh
index 7aefa8f88..daf22738f 100644
--- a/ush/config_defaults.sh
+++ b/ush/config_defaults.sh
@@ -46,6 +46,11 @@ RUN_ENVIR="nco"
 # ACCOUNT:
 # The account under which to submit jobs to the queue.
 #
+# WORKFLOW_MANAGER:
+# The workflow manager to use (e.g. rocoto). This is set to "none" by
+# default, but if the machine name is set to a platform that supports
+# rocoto, this will be overwritten and set to "rocoto".
+#
 # SCHED:
 # The job scheduler to use (e.g. slurm).  Set this to an empty string in
 # order for the experiment generation script to set it depending on the
@@ -128,6 +133,7 @@ RUN_ENVIR="nco"
 #
 MACHINE="BIG_COMPUTER"
 ACCOUNT="project_name"
+WORKFLOW_MANAGER="none"
 SCHED=""
 PARTITION_DEFAULT=""
 CLUSTERS_DEFAULT=""
@@ -141,6 +147,30 @@ QUEUE_FCST=""
 #
 #-----------------------------------------------------------------------
 #
+# Set run commands for platforms without a workflow manager. These values
+# will be ignored unless WORKFLOW_MANAGER="none".  Definitions:
+#
+# RUN_CMD_UTILS:
+# The run command for pre-processing utilities (shave, orog, sfc_climo_gen, etc.)
+# Can be left blank for smaller domains, in which case the executables will run
+# without MPI.
+#
+# RUN_CMD_FCST:
+# The run command for the model forecast step. This will be appended to the end
+# of the variable definitions file, so it can reference other variables.
+#
+# RUN_CMD_POST:
+# The run command for post-processing (UPP). Can be left blank for smaller 
+# domains, in which case UPP will run without MPI.
+#
+#-----------------------------------------------------------------------
+#
+RUN_CMD_UTILS="mpirun -np 1"
+RUN_CMD_FCST="mpirun -np \${PE_MEMBER01}"
+RUN_CMD_POST="mpirun -np 1"
+#
+#-----------------------------------------------------------------------
+#
 # Set cron-associated parameters.  Definitions:
 #
 # USE_CRON_TO_RELAUNCH:
diff --git a/ush/create_diag_table_files.sh b/ush/create_diag_table_files.sh
index cff8c0424..f2a54dc7c 100644
--- a/ush/create_diag_table_files.sh
+++ b/ush/create_diag_table_files.sh
@@ -25,7 +25,7 @@ function create_diag_table_files() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/create_model_configure_file.sh b/ush/create_model_configure_file.sh
index f64e96c07..043b3e1b7 100644
--- a/ush/create_model_configure_file.sh
+++ b/ush/create_model_configure_file.sh
@@ -25,7 +25,7 @@ function create_model_configure_file() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -97,8 +97,9 @@ run directory (run_dir):
 #
 # Set parameters in the model configure file.
 #
-  dot_quilting_dot="."${QUILTING,,}"."
-  dot_print_esmf_dot="."${PRINT_ESMF,,}"."
+
+  dot_quilting_dot="."$(echo_lowercase $QUILTING)"."
+  dot_print_esmf_dot="."$(echo_lowercase $PRINT_ESMF)"."
 #
 #-----------------------------------------------------------------------
 #
diff --git a/ush/generate_FV3LAM_wflow.sh b/ush/generate_FV3LAM_wflow.sh
index 063a9ef34..a9bdf38df 100755
--- a/ush/generate_FV3LAM_wflow.sh
+++ b/ush/generate_FV3LAM_wflow.sh
@@ -19,7 +19,11 @@ function generate_FV3LAM_wflow() {
 #
 #-----------------------------------------------------------------------
 #
-local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  if [[ $(uname -s) == Darwin ]]; then
+    local scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+  else
+    local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  fi
 local scrfunc_fn=$( basename "${scrfunc_fp}" )
 local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -299,12 +303,13 @@ $settings"
 # script to generate the experiment's actual XML file from this template
 # file.
 #
-template_xml_fp="${TEMPLATE_DIR}/${WFLOW_XML_FN}"
-$USHDIR/fill_jinja_template.py -q \
-                               -u "${settings}" \
-                               -t ${template_xml_fp} \
-                               -o ${WFLOW_XML_FP} || \
-  print_err_msg_exit "\
+if [ "${WORKFLOW_MANAGER}" = "rocoto" ]; then
+  template_xml_fp="${TEMPLATE_DIR}/${WFLOW_XML_FN}"
+  $USHDIR/fill_jinja_template.py -q \
+                                 -u "${settings}" \
+                                 -t ${template_xml_fp} \
+                                 -o ${WFLOW_XML_FP} || \
+    print_err_msg_exit "\
 Call to python script fill_jinja_template.py to create a rocoto workflow
 XML file from a template file failed.  Parameters passed to this script
 are:
@@ -315,6 +320,7 @@ are:
   Namelist settings specified on command line:
     settings =
 $settings"
+fi
 #
 #-----------------------------------------------------------------------
 #
@@ -357,7 +363,7 @@ if [ "${USE_CRON_TO_RELAUNCH}" = "TRUE" ]; then
 #
 # Make a backup copy of the user's crontab file and save it in a file.
 #
-  time_stamp=$( date "+%F_%T" )
+  time_stamp=$( $DATE_UTIL "+%F_%T" )
   crontab_backup_fp="$EXPTDIR/crontab.bak.${time_stamp}"
   print_info_msg "
 Copying contents of user cron table to backup file:
@@ -370,7 +376,7 @@ Copying contents of user cron table to backup file:
 # CRONTAB_LINE with backslashes.  Do this next.
 #
   crontab_line_esc_astr=$( printf "%s" "${CRONTAB_LINE}" | \
-                           sed -r -e "s%[*]%\\\\*%g" )
+                           $SED -r -e "s%[*]%\\\\*%g" )
 #
 # In the grep command below, the "^" at the beginning of the string be-
 # ing passed to grep is a start-of-line anchor while the "$" at the end
@@ -589,9 +595,9 @@ for (( i=0; i<${num_nml_vars}; i++ )); do
 
   mapping="${FV3_NML_VARNAME_TO_FIXam_FILES_MAPPING[$i]}"
   nml_var_name=$( printf "%s\n" "$mapping" | \
-                  sed -n -r -e "s/${regex_search}/\1/p" )
+                  $SED -n -r -e "s/${regex_search}/\1/p" )
   FIXam_fn=$( printf "%s\n" "$mapping" |
-              sed -n -r -e "s/${regex_search}/\2/p" )
+              $SED -n -r -e "s/${regex_search}/\2/p" )
 
   fp="\"\""
   if [ ! -z "${FIXam_fn}" ]; then
@@ -707,9 +713,11 @@ cp_vrfy $USHDIR/${EXPT_CONFIG_FN} $EXPTDIR
 #
 #-----------------------------------------------------------------------
 #
-wflow_db_fn="${WFLOW_XML_FN%.xml}.db"
-rocotorun_cmd="rocotorun -w ${WFLOW_XML_FN} -d ${wflow_db_fn} -v 10"
-rocotostat_cmd="rocotostat -w ${WFLOW_XML_FN} -d ${wflow_db_fn} -v 10"
+if [ "${WORKFLOW_MANAGER}" = "rocoto" ]; then
+  wflow_db_fn="${WFLOW_XML_FN%.xml}.db"
+  rocotorun_cmd="rocotorun -w ${WFLOW_XML_FN} -d ${wflow_db_fn} -v 10"
+  rocotostat_cmd="rocotostat -w ${WFLOW_XML_FN} -d ${wflow_db_fn} -v 10"
+fi
 
 print_info_msg "
 ========================================================================
@@ -725,37 +733,24 @@ The experiment directory is:
   > EXPTDIR=\"$EXPTDIR\"
 
 "
-case $MACHINE in
-
-"CHEYENNE")
+#
+#-----------------------------------------------------------------------
+#
+# If rocoto is required, print instructions on how to load and use it
+#
+#-----------------------------------------------------------------------
+#
+if [ "${WORKFLOW_MANAGER}" = "rocoto" ]; then
   print_info_msg "\
 To launch the workflow, first ensure that you have a compatible version
-of rocoto in your \$PATH. On Cheyenne, version 1.3.1 has been pre-built;
-you can load it in your \$PATH with one of the following commands, depending
-on your default shell:
+of rocoto available. For most pre-configured platforms, rocoto can be
+loaded via a module:
 
-bash:
-  > export PATH=\${PATH}:/glade/p/ral/jntp/tools/rocoto/rocoto-1.3.1/bin/
+  > module load rocoto
 
-tcsh:
-  > setenv PATH \${PATH}:/glade/p/ral/jntp/tools/rocoto/rocoto-1.3.1/bin/
-"
-  ;;
+For more details on rocoto, see the User's Guide.
 
-*)
-  print_info_msg "\
-To launch the workflow, first ensure that you have a compatible version
-of rocoto loaded.  For example, to load version 1.3.1 of rocoto, use
 
-  > module load rocoto/1.3.1
-
-(This version has been tested on hera; later versions may also work but
-have not been tested.)
-"
-  ;;
-
-esac
-print_info_msg "
 To launch the workflow, change location to the experiment directory
 (EXPTDIR) and issue the rocotrun command, as follows:
 
@@ -785,6 +780,7 @@ edit the cron table):
 
 Done.
 "
+fi
 #
 # If necessary, run the NOMADS script to source external model data.
 #
@@ -828,7 +824,12 @@ set -u
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+if [[ $(uname -s) == Darwin ]]; then
+  command -v greadlink >/dev/null 2>&1 || { echo >&2 "For Darwin-based operating systems (MacOS), the 'greadlink' utility is required to run the UFS SRW Application. Reference the User's Guide for more information about platform requirements. Aborting."; exit 1; }
+  scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+else
+  scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+fi
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -881,27 +882,29 @@ echo "$retval" >> "${tmp_fp}"
 # place in a subshell (due to the fact that we are then piping its out-
 # put to the "tee" command).  Then remove the temporary file.
 #
-exptdir=$( sed "1q;d" "${tmp_fp}" )
-retval=$( sed "2q;d" "${tmp_fp}" )
-rm "${tmp_fp}"
+if [ -f "${tmp_fp}" ]; then
+  exptdir=$( sed "1q;d" "${tmp_fp}" )
+  retval=$( sed "2q;d" "${tmp_fp}" )
+  rm "${tmp_fp}"
 #
 # If the call to the generate_FV3LAM_wflow function above was success-
 # ful, move the log file in which the "tee" command saved the output of
 # the function to the experiment directory.
 #
-if [ $retval -eq 0 ]; then
-  mv "${log_fp}" "$exptdir"
+  if [ $retval -eq 0 ]; then
+    mv "${log_fp}" "$exptdir"
 #
 # If the call to the generate_FV3LAM_wflow function above was not suc-
 # cessful, print out an error message and exit with a nonzero return
 # code.
 #
-else
-  printf "
-Experiment/workflow generation failed.  Check the log file from the ex-
-periment/workflow generation script in the file specified by log_fp:
-  log_fp = \"${log_fp}\"
-Stopping.
-"
-  exit 1
+  else
+    printf "
+  Experiment/workflow generation failed.  Check the log file from the ex-
+  periment/workflow generation script in the file specified by log_fp:
+    log_fp = \"${log_fp}\"
+  Stopping.
+  "
+    exit 1
+  fi
 fi
diff --git a/ush/get_extrn_mdl_file_dir_info.sh b/ush/get_extrn_mdl_file_dir_info.sh
index 69a3f69b5..ae734f00c 100755
--- a/ush/get_extrn_mdl_file_dir_info.sh
+++ b/ush/get_extrn_mdl_file_dir_info.sh
@@ -37,7 +37,7 @@ function get_extrn_mdl_file_dir_info() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -166,7 +166,7 @@ where the arguments are defined as follows:
  
   varname_extrn_mdl_sysdir:
   Name of the global variable that will contain the system directory in
-  which the externaml model output files may be stored.
+  which the external model output files may be stored.
  
   varname_extrn_mdl_arcv_fmt:
   Name of the global variable that will contain the format of the ar-
@@ -213,7 +213,7 @@ fi
 #
 #-----------------------------------------------------------------------
 #
-  anl_or_fcst="${anl_or_fcst^^}"
+  anl_or_fcst=$(echo_uppercase $anl_or_fcst)
   valid_vals_anl_or_fcst=( "ANL" "FCST" )
   check_var_valid_value "anl_or_fcst" "valid_vals_anl_or_fcst"
 #
@@ -234,7 +234,7 @@ fi
   hh=${cdate_FV3LAM:8:2}
   yyyymmdd=${cdate_FV3LAM:0:8}
 
-  cdate=$( date --utc --date "${yyyymmdd} ${hh} UTC - ${time_offset_hrs} hours" "+%Y%m%d%H" )
+  cdate=$( $DATE_UTIL --utc --date "${yyyymmdd} ${hh} UTC - ${time_offset_hrs} hours" "+%Y%m%d%H" )
 #
 #-----------------------------------------------------------------------
 #
@@ -298,7 +298,7 @@ fi
 # Get the Julian day-of-year of the starting date and time of the exter-
 # nal model forecast.
 #
-    ddd=$( date --utc --date "${yyyy}-${mm}-${dd} ${hh}:${mn} UTC" "+%j" )
+    ddd=$( $DATE_UTIL --utc --date "${yyyy}-${mm}-${dd} ${hh}:${mn} UTC" "+%j" )
 #
 # Get the last two digits of the year of the starting date and time of 
 # the external model forecast.
@@ -559,6 +559,7 @@ bination of external model (extrn_mdl_name) and analysis or forecast
     sysbasedir="${EXTRN_MDL_SYSBASEDIR_LBCS}"
   fi
 
+  sysdir=""
   case "${extrn_mdl_name}" in
 
 #
@@ -595,11 +596,13 @@ bination of external model (extrn_mdl_name) and analysis or forecast
       sysdir=""
       ;;
     *)
-      print_err_msg_exit "\
+      if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+        print_err_msg_exit "\
 The system directory in which to look for external model output files 
 has not been specified for this external model and machine combination:
   extrn_mdl_name = \"${extrn_mdl_name}\"
   MACHINE = \"$MACHINE\""
+      fi
       ;;
     esac
     ;;
@@ -635,11 +638,13 @@ has not been specified for this external model and machine combination:
       sysdir="$sysbasedir"
       ;;
     *)
-      print_err_msg_exit "\
+      if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+        print_err_msg_exit "\
 The system directory in which to look for external model output files 
 has not been specified for this external model and machine combination:
   extrn_mdl_name = \"${extrn_mdl_name}\"
   MACHINE = \"$MACHINE\""
+      fi
       ;;
     esac
     ;;
@@ -675,11 +680,13 @@ has not been specified for this external model and machine combination:
       sysdir="$sysbasedir"
       ;;
     *)
-      print_err_msg_exit "\
+      if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+        print_err_msg_exit "\
 The system directory in which to look for external model output files 
 has not been specified for this external model and machine combination:
   extrn_mdl_name = \"${extrn_mdl_name}\"
   MACHINE = \"$MACHINE\""
+      fi
       ;;
     esac
     ;;
@@ -715,11 +722,13 @@ has not been specified for this external model and machine combination:
       sysdir="$sysbasedir"
       ;;
     *)
-      print_err_msg_exit "\
+      if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+        print_err_msg_exit "\
 The system directory in which to look for external model output files 
 has not been specified for this external model and machine combination:
   extrn_mdl_name = \"${extrn_mdl_name}\"
   MACHINE = \"$MACHINE\""
+      fi
       ;;
     esac
     ;;
@@ -754,22 +763,25 @@ has not been specified for this external model and machine combination:
       sysdir="$sysbasedir"
       ;;
     *)
-      print_err_msg_exit "\
+      if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+        print_err_msg_exit "\
 The system directory in which to look for external model output files
 has not been specified for this external model and machine combination:
   extrn_mdl_name = \"${extrn_mdl_name}\"
   MACHINE = \"$MACHINE\""
+      fi
       ;;
     esac
     ;;
 
 
   *)
-    print_err_msg_exit "\
+    if [ "${USE_USER_STAGED_EXTRN_FILES}" != "TRUE" ]; then
+      print_err_msg_exit "\
 The system directory in which to look for external model output files 
 has not been specified for this external model:
   extrn_mdl_name = \"${extrn_mdl_name}\""
-
+    fi
   esac
 #
 #-----------------------------------------------------------------------
diff --git a/ush/launch_FV3LAM_wflow.sh b/ush/launch_FV3LAM_wflow.sh
index 24e9088a4..ebf1336df 100755
--- a/ush/launch_FV3LAM_wflow.sh
+++ b/ush/launch_FV3LAM_wflow.sh
@@ -17,7 +17,12 @@ set -u
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+if [[ $(uname -s) == Darwin ]]; then
+  command -v greadlink >/dev/null 2>&1 || { echo >&2 "For Darwin-based operating systems (MacOS), the 'greadlink' utility is required to run the UFS SRW Application. Reference the User's Guide for more information about platform requirements. Aborting."; exit 1; }
+  scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+else
+  scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+fi
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -65,7 +70,12 @@ scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #-----------------------------------------------------------------------
 #
 exptdir=$( dirname "$0" )
-exptdir=$( readlink -f "$exptdir" )
+if [[ $(uname -s) == Darwin ]]; then
+  command -v greadlink >/dev/null 2>&1 || { echo >&2 "For Darwin-based operating systems (MacOS), the 'greadlink' utility is required to run the UFS SRW Application. Reference the User's Guide for more information about platform requirements. Aborting."; exit 1; }
+  exptdir=$( greadlink -f "$exptdir" )
+else
+  exptdir=$( readlink -f "$exptdir" )
+fi
 #
 #-----------------------------------------------------------------------
 #
@@ -301,8 +311,8 @@ while read -r line; do
 #
   if [ $i -gt 0 ]; then
     im1=$((i-1))
-    cycle_str[im1]=$( echo "$line" | sed -r -n -e "s/${regex_search}/\1/p" )
-    cycle_status[im1]=$( echo "$line" | sed -r -n -e "s/${regex_search}/\2/p" )
+    cycle_str[im1]=$( echo "$line" | $SED -r -n -e "s/${regex_search}/\1/p" )
+    cycle_status[im1]=$( echo "$line" | $SED -r -n -e "s/${regex_search}/\2/p" )
   fi
   i=$((i+1))
 done <<< "${rocotostat_output}"
@@ -397,7 +407,7 @@ launch script for this experiment:
 # CRONTAB_LINE with backslashes.  Do this next.
 #
     crontab_line_esc_astr=$( printf "%s" "${CRONTAB_LINE}" | \
-                             sed -r -e "s%[*]%\\\\*%g" )
+                             $SED -r -e "s%[*]%\\\\*%g" )
 #
 # In the string passed to the grep command below, we use the line start
 # and line end anchors ("^" and "$", respectively) to ensure that we on-
diff --git a/ush/link_fix.sh b/ush/link_fix.sh
index 651f4fbfd..06c71d5e1 100755
--- a/ush/link_fix.sh
+++ b/ush/link_fix.sh
@@ -26,7 +26,7 @@ function link_fix() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -283,7 +283,7 @@ Creating links in the FIXLAM directory to the grid files..."
 
     fn=$( basename $fp )
   
-    res=$( printf "%s" $fn | sed -n -r -e "s/^C([0-9]*).*/\1/p" )
+    res=$( printf "%s" $fn | $SED -n -r -e "s/^C([0-9]*).*/\1/p" )
     if [ -z $res ]; then
       print_err_msg_exit "\
 The resolution could not be extracted from the current file's name.  The
diff --git a/ush/load_modules_run_task.sh b/ush/load_modules_run_task.sh
index 05bb99238..05b7d248f 100755
--- a/ush/load_modules_run_task.sh
+++ b/ush/load_modules_run_task.sh
@@ -27,7 +27,7 @@
 #
 #-----------------------------------------------------------------------
 #
-scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 scrfunc_fn=$( basename "${scrfunc_fp}" )
 scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -156,7 +156,7 @@ jjob_fp="$2"
 #
 #-----------------------------------------------------------------------
 #
-machine=${MACHINE,,}
+machine=$(echo_lowercase $MACHINE)
 env_fn="build_${machine}_${COMPILER}.env"
 env_fp="${SR_WX_APP_TOP_DIR}/env/${env_fn}"
 source "${env_fp}" || print_err_msg_exit "\
@@ -228,11 +228,11 @@ use_default_modulefile=0
 
 #else
 
-#  modulefile_path=$( readlink -f "${modules_dir}/${modulefile_name}" )
+#  modulefile_path=$( $READLINK -f "${modules_dir}/${modulefile_name}" )
 
 #  if [ ! -f "${modulefile_path}" ]; then
 
-#    default_modulefile_path=$( readlink -f "${default_modules_dir}/${default_modulefile_name}" )
+#    default_modulefile_path=$( $READLINK -f "${default_modules_dir}/${default_modulefile_name}" )
 #    if [ -f "${default_modulefile_path}" ]; then
 #
 # If the task-specific modulefile does not exist but a default one does, 
diff --git a/ush/make_grid_mosaic_file.sh b/ush/make_grid_mosaic_file.sh
index 0026cb86a..fd280a027 100644
--- a/ush/make_grid_mosaic_file.sh
+++ b/ush/make_grid_mosaic_file.sh
@@ -27,7 +27,11 @@ function make_grid_mosaic_file() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  if [[ $(uname -s) == Darwin ]]; then
+    local scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+  else
+    local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  fi
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/set_FV3nml_sfc_climo_filenames.sh b/ush/set_FV3nml_sfc_climo_filenames.sh
index 2d44a9d0c..13f2ecdf5 100644
--- a/ush/set_FV3nml_sfc_climo_filenames.sh
+++ b/ush/set_FV3nml_sfc_climo_filenames.sh
@@ -30,7 +30,7 @@ function set_FV3nml_sfc_climo_filenames() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -145,9 +145,9 @@ for (( i=0; i<${num_nml_vars}; i++ )); do
 
   mapping="${FV3_NML_VARNAME_TO_SFC_CLIMO_FIELD_MAPPING[$i]}"
   nml_var_name=$( printf "%s\n" "$mapping" | \
-                  sed -n -r -e "s/${regex_search}/\1/p" )
+                  $SED -n -r -e "s/${regex_search}/\1/p" )
   sfc_climo_field_name=$( printf "%s\n" "$mapping" |
-                          sed -n -r -e "s/${regex_search}/\2/p" )
+                          $SED -n -r -e "s/${regex_search}/\2/p" )
 #
 # Check that the surface climatology field associated with the current
 # namelist variable is valid.
diff --git a/ush/set_FV3nml_stoch_params.sh b/ush/set_FV3nml_stoch_params.sh
index 98e1c3469..61e5bcec9 100644
--- a/ush/set_FV3nml_stoch_params.sh
+++ b/ush/set_FV3nml_stoch_params.sh
@@ -33,7 +33,7 @@ function set_FV3nml_stoch_params() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/set_cycle_dates.sh b/ush/set_cycle_dates.sh
index b8d406c12..c4b3adfbf 100644
--- a/ush/set_cycle_dates.sh
+++ b/ush/set_cycle_dates.sh
@@ -30,7 +30,7 @@ function set_cycle_dates() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -106,7 +106,7 @@ End date (date_end) must be at or after start date (date_start):
   date_crnt="${date_start}"
   while [ "${date_crnt}" -le "${date_end}" ]; do
     all_cdates+=( $( printf "%s " ${cycle_hrs[@]/#/${date_crnt}} ) )
-    date_crnt=$( date -d "${date_crnt} + 1 days" +%Y%m%d )
+    date_crnt=$( $DATE_UTIL -d "${date_crnt} + 1 days" +%Y%m%d )
   done
 #
 #-----------------------------------------------------------------------
diff --git a/ush/set_extrn_mdl_params.sh b/ush/set_extrn_mdl_params.sh
index 9554d6a32..67968cc94 100644
--- a/ush/set_extrn_mdl_params.sh
+++ b/ush/set_extrn_mdl_params.sh
@@ -17,7 +17,7 @@ function set_extrn_mdl_params() {
 #
 #-----------------------------------------------------------------------
 #
-local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 local scrfunc_fn=$( basename "${scrfunc_fp}" )
 local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -49,25 +49,12 @@ if [ "${RUN_ENVIR}" = "nco" ]; then
 
 else
 
+  EXTRN_MDL_SYSBASEDIR_ICS=""
+
   case ${EXTRN_MDL_NAME_ICS} in
 
   "GSMGFS")
     case $MACHINE in
-    "WCOSS_CRAY")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
-    "WCOSS_DELL_P3")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
-    "HERA")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
-    "JET")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
     "ODIN")
       EXTRN_MDL_SYSBASEDIR_ICS="/scratch/ywang/EPIC/GDAS/2019053000_mem001"
       ;;
@@ -94,9 +81,6 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_ICS="/scratch1/NCEPDEV/rstprod/com/gfs/prod"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_ICS="/public/data/grids/gfs/nemsio"
       ;;
@@ -120,9 +104,6 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_ICS="/scratch2/BMC/public/data/gsd/rap/full/wrfnat"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_ICS="/misc/whome/rtrr/rap"
       ;;
@@ -140,9 +121,6 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_ICS="/scratch2/BMC/public/data/gsd/hrrr/conus/wrfnat"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_ICS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_ICS="/misc/whome/rtrr/hrrr"
       ;;
@@ -159,17 +137,24 @@ else
 
 fi
 #
-# If EXTRN_MDL_SYSBASEDIR_ICS has not been set (not even to a null string), 
-# print out an error message and exit.
+# If EXTRN_MDL_SYSBASEDIR_ICS has not been set, check if user has specified their own 
+# input data or HPSS_QUEUE is set (in order to pull data from HPSS at runtime). If 
+# none of these avenues for getting data are available, print out an error message and 
+# exit.
 #
-if [ -z "${EXTRN_MDL_SYSBASEDIR_ICS+x}" ]; then
+if [ "${USE_USER_STAGED_EXTRN_FILES}" = "FALSE" -a -z "${EXTRN_MDL_SYSBASEDIR_ICS}" -a -z "${QUEUE_HPSS}" ]; then
   print_err_msg_exit "\
-The variable EXTRN_MDL_SYSBASEDIR_ICS specifying the system directory
-in which to look for the files generated by the external model for ICs
-has not been set for the current combination of machine (MACHINE) and 
-external model (EXTRN_MDL_NAME_ICS):
+
+No source of initial condition files has been set for this combination
+of machine (MACHINE) and external model (EXTRN_MDL_NAME_ICS), and there
+is no HPSS_QUEUE specified to pull data from HPSS. Check those values
+to ensure that data is available for your machine, or stage your own
+data by setting USE_USER_STAGED_EXTRN_FILES = TRUE in config.sh. See
+the users guide for additional information on staging input data.
   MACHINE = \"$MACHINE\"
-  EXTRN_MDL_NAME_ICS = \"${EXTRN_MDL_NAME_ICS}\""
+  EXTRN_MDL_NAME_ICS = \"${EXTRN_MDL_NAME_ICS}\"
+  USE_USER_STAGED_EXTRN_FILES = \"${USE_USER_STAGED_EXTRN_FILES}\""
+
 fi
 #
 #-----------------------------------------------------------------------
@@ -215,25 +200,12 @@ if [ "${RUN_ENVIR}" = "nco" ]; then
 
 else
 
+  EXTRN_MDL_SYSBASEDIR_LBCS=""
+
   case ${EXTRN_MDL_NAME_LBCS} in
 
   "GSMGFS")
     case $MACHINE in
-    "WCOSS_CRAY")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
-    "WCOSS_DELL_P3")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
-    "HERA")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
-    "JET")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
     "ODIN")
       EXTRN_MDL_SYSBASEDIR_LBCS="/scratch/ywang/EPIC/GDAS/2019053000_mem001"
       ;;
@@ -257,9 +229,6 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_LBCS="/scratch1/NCEPDEV/rstprod/com/gfs/prod"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_LBCS="/public/data/grids/gfs/nemsio"
       ;;
@@ -283,15 +252,9 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_LBCS="/scratch2/BMC/public/data/gsd/rap/full/wrfnat"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_LBCS="/misc/whome/rtrr/rap"
       ;;
-    "CHEYENNE")
-      EXTRN_MDL_SYSBASEDIR_LBCS="dummy_value"
-      ;;
     esac
     ;;
 
@@ -300,9 +263,6 @@ else
     "HERA")
       EXTRN_MDL_SYSBASEDIR_LBCS="/scratch2/BMC/public/data/gsd/hrrr/conus/wrfnat"
       ;;
-    "ORION")
-      EXTRN_MDL_SYSBASEDIR_LBCS=""
-      ;;
     "JET")
       EXTRN_MDL_SYSBASEDIR_LBCS="/misc/whome/rtrr/hrrr"
       ;;
@@ -313,17 +273,21 @@ else
 
 fi
 #
-# If EXTRN_MDL_SYSBASEDIR_LBCS has not been set (not even to a null string), 
-# print out an error message and exit.
+# If EXTRN_MDL_SYSBASEDIR_LBCS has not been set, check if user has specified their own
+# input data or HPSS_QUEUE is set (in order to pull data from HPSS at runtime). If 
+# none of these avenues for getting data are available, print out an error message and 
+# exit.
 #
-if [ -z "${EXTRN_MDL_SYSBASEDIR_LBCS+x}" ]; then
+if [ "${USE_USER_STAGED_EXTRN_FILES}" = "FALSE" -a -z "${EXTRN_MDL_SYSBASEDIR_LBCS}" -a -z "${QUEUE_HPSS}" ]; then
   print_err_msg_exit "\
-The variable EXTRN_MDL_SYSBASEDIR_LBCS specifying the system directory
-in which to look for the files generated by the external model for LBCs
-has not been set for the current combination of machine (MACHINE) and 
-external model (EXTRN_MDL_NAME_LBCS):
+of machine (MACHINE) and external model (EXTRN_MDL_NAME_LBCS), and there
+is no HPSS_QUEUE specified to pull data from HPSS. Check those values
+to ensure that data is available for your machine, or stage your own 
+data by setting USE_USER_STAGED_EXTRN_FILES = TRUE in config.sh. See
+the users guide for additional information on staging input data.
   MACHINE = \"$MACHINE\"
-  EXTRN_MDL_NAME_LBCS = \"${EXTRN_MDL_NAME_LBCS}\""
+  EXTRN_MDL_NAME_LBCS = \"${EXTRN_MDL_NAME_LBCS}\"
+  USE_USER_STAGED_EXTRN_FILES = \"${USE_USER_STAGED_EXTRN_FILES}\""
 fi
 }
 #
diff --git a/ush/set_gridparams_ESGgrid.sh b/ush/set_gridparams_ESGgrid.sh
index 8cef16ee3..1b86c99aa 100644
--- a/ush/set_gridparams_ESGgrid.sh
+++ b/ush/set_gridparams_ESGgrid.sh
@@ -26,7 +26,7 @@ function set_gridparams_ESGgrid() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/set_gridparams_GFDLgrid.sh b/ush/set_gridparams_GFDLgrid.sh
index 7d47affb1..a76b9a58a 100644
--- a/ush/set_gridparams_GFDLgrid.sh
+++ b/ush/set_gridparams_GFDLgrid.sh
@@ -26,7 +26,7 @@ function set_gridparams_GFDLgrid() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -425,8 +425,8 @@ AFTER adjustments are:
   nx_of_t6_on_t6sg=$(( 2*nx_of_t6_on_t6g ))
   ny_of_t6_on_t6sg=$(( 2*ny_of_t6_on_t6g ))
 
-  prime_factors_nx_of_t7_on_t7g=$( factor ${nx_of_t7_on_t7g} | sed -r -e 's/^[0-9]+: (.*)/\1/' )
-  prime_factors_ny_of_t7_on_t7g=$( factor ${ny_of_t7_on_t7g} | sed -r -e 's/^[0-9]+: (.*)/\1/' )
+  prime_factors_nx_of_t7_on_t7g=$( factor ${nx_of_t7_on_t7g} | $SED -r -e 's/^[0-9]+: (.*)/\1/' )
+  prime_factors_ny_of_t7_on_t7g=$( factor ${ny_of_t7_on_t7g} | $SED -r -e 's/^[0-9]+: (.*)/\1/' )
 
   print_info_msg "$VERBOSE" "
 The number of cells in the two horizontal directions (x and y) on the 
diff --git a/ush/set_ozone_param.sh b/ush/set_ozone_param.sh
index 5fb90f839..c85749279 100644
--- a/ush/set_ozone_param.sh
+++ b/ush/set_ozone_param.sh
@@ -44,7 +44,7 @@ function set_ozone_param() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -130,7 +130,7 @@ function set_ozone_param() {
 #-----------------------------------------------------------------------
 #
   regex_search="^[ ]*<scheme>(ozphys.*)<\/scheme>[ ]*$"
-  ozone_param=$( sed -r -n -e "s/${regex_search}/\1/p" "${ccpp_phys_suite_fp}" )
+  ozone_param=$( $SED -r -n -e "s/${regex_search}/\1/p" "${ccpp_phys_suite_fp}" )
 
   if [ "${ozone_param}" = "ozphys_2015" ]; then
     fixgsm_ozone_fn="ozprdlos_2015_new_sbuvO3_tclm15_nuchem.f77"
@@ -175,11 +175,11 @@ num_symlinks=${#CYCLEDIR_LINKS_TO_FIXam_FILES_MAPPING[@]}
 for (( i=0; i<${num_symlinks}; i++ )); do
   mapping="${CYCLEDIR_LINKS_TO_FIXam_FILES_MAPPING[$i]}"
   symlink=$( printf "%s\n" "$mapping" | \
-             sed -n -r -e "s/${regex_search}/\1/p" )
+             $SED -n -r -e "s/${regex_search}/\1/p" )
   if [ "$symlink" = "${ozone_symlink}" ]; then
     regex_search="^[ ]*([^| ]+[ ]*)[|][ ]*([^| ]*)[ ]*$"
     mapping_ozone=$( printf "%s\n" "$mapping" | \
-                     sed -n -r -e "s/${regex_search}/\1/p" )
+                     $SED -n -r -e "s/${regex_search}/\1/p" )
     mapping_ozone="${mapping_ozone}| ${fixgsm_ozone_fn}"
     CYCLEDIR_LINKS_TO_FIXam_FILES_MAPPING[$i]="${mapping_ozone}"
     fixgsm_ozone_fn_is_set="TRUE"
diff --git a/ush/set_predef_grid_params.sh b/ush/set_predef_grid_params.sh
index e87e9ecdb..1dde42871 100644
--- a/ush/set_predef_grid_params.sh
+++ b/ush/set_predef_grid_params.sh
@@ -16,7 +16,7 @@ function set_predef_grid_params() {
 #
 #-----------------------------------------------------------------------
 #
-local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 local scrfunc_fn=$( basename "${scrfunc_fp}" )
 local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
diff --git a/ush/set_thompson_mp_fix_files.sh b/ush/set_thompson_mp_fix_files.sh
index 7b87c8fc1..19ad295fc 100644
--- a/ush/set_thompson_mp_fix_files.sh
+++ b/ush/set_thompson_mp_fix_files.sh
@@ -30,7 +30,7 @@ function set_thompson_mp_fix_files() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -89,7 +89,7 @@ function set_thompson_mp_fix_files() {
 #
   thompson_mp_name="mp_thompson"
   regex_search="^[ ]*<scheme>(${thompson_mp_name})<\/scheme>[ ]*$"
-  thompson_mp_name_or_null=$( sed -r -n -e "s/${regex_search}/\1/p" "${ccpp_phys_suite_fp}" )
+  thompson_mp_name_or_null=$( $SED -r -n -e "s/${regex_search}/\1/p" "${ccpp_phys_suite_fp}" )
 
   if [ "${thompson_mp_name_or_null}" = "${thompson_mp_name}" ]; then
     thompson_mp_is_used="TRUE"
diff --git a/ush/setup.sh b/ush/setup.sh
index c5c146527..fc9d3c20c 100755
--- a/ush/setup.sh
+++ b/ush/setup.sh
@@ -1,3 +1,4 @@
+#!/bin/bash
 #
 #-----------------------------------------------------------------------
 #
@@ -23,7 +24,7 @@ function setup() {
 #
 #-----------------------------------------------------------------------
 #
-local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+local scrfunc_fp=$( $READLINK -f "${BASH_SOURCE[0]}" )
 local scrfunc_fn=$( basename "${scrfunc_fp}" )
 local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -139,7 +140,7 @@ check_var_valid_value "VERBOSE" "valid_vals_VERBOSE"
 # Set VERBOSE to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-VERBOSE=${VERBOSE^^}
+VERBOSE=$(echo_uppercase $VERBOSE)
 if [ "$VERBOSE" = "TRUE" ] || \
    [ "$VERBOSE" = "YES" ]; then
   VERBOSE="TRUE"
@@ -159,7 +160,7 @@ check_var_valid_value "USE_CRON_TO_RELAUNCH" "valid_vals_USE_CRON_TO_RELAUNCH"
 # Set USE_CRON_TO_RELAUNCH to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-USE_CRON_TO_RELAUNCH=${USE_CRON_TO_RELAUNCH^^}
+USE_CRON_TO_RELAUNCH=$(echo_uppercase  $USE_CRON_TO_RELAUNCH)
 if [ "${USE_CRON_TO_RELAUNCH}" = "TRUE" ] || \
    [ "${USE_CRON_TO_RELAUNCH}" = "YES" ]; then
   USE_CRON_TO_RELAUNCH="TRUE"
@@ -179,7 +180,7 @@ check_var_valid_value "RUN_TASK_MAKE_GRID" "valid_vals_RUN_TASK_MAKE_GRID"
 # Set RUN_TASK_MAKE_GRID to either "TRUE" or "FALSE" so we don't have to
 # consider other valid values later on.
 #
-RUN_TASK_MAKE_GRID=${RUN_TASK_MAKE_GRID^^}
+RUN_TASK_MAKE_GRID=$(echo_uppercase $RUN_TASK_MAKE_GRID)
 if [ "${RUN_TASK_MAKE_GRID}" = "TRUE" ] || \
    [ "${RUN_TASK_MAKE_GRID}" = "YES" ]; then
   RUN_TASK_MAKE_GRID="TRUE"
@@ -200,7 +201,7 @@ check_var_valid_value \
 # Set RUN_TASK_MAKE_SFC_CLIMO to either "TRUE" or "FALSE" so we don't
 # have to consider other valid values later on.
 #
-RUN_TASK_MAKE_SFC_CLIMO=${RUN_TASK_MAKE_SFC_CLIMO^^}
+RUN_TASK_MAKE_SFC_CLIMO=$(echo_uppercase $RUN_TASK_MAKE_SFC_CLIMO)
 if [ "${RUN_TASK_MAKE_SFC_CLIMO}" = "TRUE" ] || \
    [ "${RUN_TASK_MAKE_SFC_CLIMO}" = "YES" ]; then
   RUN_TASK_MAKE_SFC_CLIMO="TRUE"
@@ -242,7 +243,7 @@ check_var_valid_value "DO_SHUM" "valid_vals_DO_SHUM"
 # Set DO_SHUM to either "TRUE" or "FALSE" so we don't
 # have to consider other valid values later on.
 #
-DO_SHUM=${DO_SHUM^^}
+DO_SHUM=$(echo_uppercase $DO_SHUM)
 if [ "${DO_SHUM}" = "TRUE" ] || \
    [ "${DO_SHUM}" = "YES" ]; then
   DO_SHUM="TRUE"
@@ -262,7 +263,7 @@ check_var_valid_value "DO_SPPT" "valid_vals_DO_SPPT"
 # Set DO_SPPT to either "TRUE" or "FALSE" so we don't
 # have to consider other valid values later on.
 #
-DO_SPPT=${DO_SPPT^^}
+DO_SPPT=$(echo_uppercase $DO_SPPT)
 if [ "${DO_SPPT}" = "TRUE" ] || \
    [ "${DO_SPPT}" = "YES" ]; then
   DO_SPPT="TRUE"
@@ -282,7 +283,7 @@ check_var_valid_value "DO_SKEB" "valid_vals_DO_SKEB"
 # Set DO_SKEB to either "TRUE" or "FALSE" so we don't
 # have to consider other valid values later on.
 #
-DO_SKEB=${DO_SKEB^^}
+DO_SKEB=$(echo_uppercase $DO_SKEB)
 if [ "${DO_SKEB}" = "TRUE" ] || \
    [ "${DO_SKEB}" = "YES" ]; then
   DO_SKEB="TRUE"
@@ -323,7 +324,7 @@ check_var_valid_value "USE_FVCOM" "valid_vals_USE_FVCOM"
 # Set USE_FVCOM to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-USE_FVCOM=${USE_FVCOM^^}
+USE_FVCOM=$(echo_uppercase $USE_FVCOM)
 if [ "$USE_FVCOM" = "TRUE" ] || \
    [ "$USE_FVCOM" = "YES" ]; then
   USE_FVCOM="TRUE"
@@ -347,7 +348,7 @@ check_var_valid_value "DOT_OR_USCORE" "valid_vals_DOT_OR_USCORE"
 #
 #-----------------------------------------------------------------------
 #
-MACHINE=$( printf "%s" "$MACHINE" | sed -e 's/\(.*\)/\U\1/' )
+MACHINE=$( printf "%s" "$MACHINE" | $SED -e 's/\(.*\)/\U\1/' )
 check_var_valid_value "MACHINE" "valid_vals_MACHINE"
 #
 #-----------------------------------------------------------------------
@@ -358,10 +359,12 @@ check_var_valid_value "MACHINE" "valid_vals_MACHINE"
 #
 #-----------------------------------------------------------------------
 #
+NCORES_PER_NODE=""
 case $MACHINE in
 
   "WCOSS_CRAY")
-    NCORES_PER_NODE="24"
+    WORKFLOW_MANAGER="rocoto"
+    NCORES_PER_NODE=24
     SCHED="lsfcray"
     QUEUE_DEFAULT=${QUEUE_DEFAULT:-"dev"}
     QUEUE_HPSS=${QUEUE_HPSS:-"dev_transfer"}
@@ -369,6 +372,7 @@ case $MACHINE in
     ;;
 
   "WCOSS_DELL_P3")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=24
     SCHED="lsf"
     QUEUE_DEFAULT=${QUEUE_DEFAULT:-"dev"}
@@ -377,6 +381,7 @@ case $MACHINE in
     ;;
 
   "HERA")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=40
     SCHED="${SCHED:-slurm}"
     PARTITION_DEFAULT=${PARTITION_DEFAULT:-"hera"}
@@ -388,6 +393,7 @@ case $MACHINE in
     ;;
 
   "ORION")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=40
     SCHED="${SCHED:-slurm}"
     PARTITION_DEFAULT=${PARTITION_DEFAULT:-"orion"}
@@ -399,6 +405,7 @@ case $MACHINE in
     ;;
 
   "JET")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=24
     SCHED="${SCHED:-slurm}"
     PARTITION_DEFAULT=${PARTITION_DEFAULT:-"sjet,vjet,kjet,xjet"}
@@ -410,6 +417,7 @@ case $MACHINE in
     ;;
 
   "ODIN")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=24
     SCHED="${SCHED:-slurm}"
     PARTITION_DEFAULT=${PARTITION_DEFAULT:-"workq"}
@@ -421,6 +429,7 @@ case $MACHINE in
     ;;
 
   "CHEYENNE")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=36
     SCHED="${SCHED:-pbspro}"
     QUEUE_DEFAULT=${QUEUE_DEFAULT:-"regular"}
@@ -429,6 +438,7 @@ case $MACHINE in
     ;;
 
   "STAMPEDE")
+    WORKFLOW_MANAGER="rocoto"
     NCORES_PER_NODE=68
     SCHED="slurm"
     PARTITION_DEFAULT=${PARTITION_DEFAULT:-"normal"}
@@ -450,6 +460,16 @@ case $MACHINE in
     CLUSTERS_FCST=${CLUSTERS_FCST:-"c4"}
     QUEUE_FCST=${QUEUE_FCST:-"normal"}
     ;;
+    
+  "MACOS")
+    WORKFLOW_MANAGER="none"
+    SCHED="none"
+    ;;
+
+  "LINUX")
+    WORKFLOW_MANAGER="none"
+    SCHED="none"
+    ;;
 
 esac
 #
@@ -459,20 +479,26 @@ esac
 #
 #-----------------------------------------------------------------------
 #
-SCHED="${SCHED,,}"
+SCHED=$(echo_lowercase $SCHED)
 check_var_valid_value "SCHED" "valid_vals_SCHED"
-#
 #-----------------------------------------------------------------------
 #
-# Verify that the ACCOUNT variable is not empty.  If it is, print out an
-# error message and exit.
+# If we are using a workflow manager, run some checks. First, 
+# verify that the ACCOUNT variable is not empty. Second, ensure that the
+# custom RUN_CMD variables are not set.
 #
 #-----------------------------------------------------------------------
 #
-if [ -z "$ACCOUNT" ]; then
-  print_err_msg_exit "\
-The variable ACCOUNT cannot be empty:
-  ACCOUNT = \"$ACCOUNT\""
+if [ "$WORKFLOW_MANAGER" != "none" ]; then
+  if [ -z "$ACCOUNT" ]; then
+    print_err_msg_exit "\
+The variable ACCOUNT cannot be empty if you are using a workflow manager:
+  ACCOUNT = \"$ACCOUNT\"
+  WORKFLOW_MANAGER = \"$WORKFLOW_MANAGER\""
+  fi
+  RUN_CMD_UTILS=""
+  RUN_CMD_FCST=""
+  RUN_CMD_POST=""
 fi
 #
 #-----------------------------------------------------------------------
@@ -541,7 +567,7 @@ check_var_valid_value \
 #-----------------------------------------------------------------------
 #
 DATE_OR_NULL=$( printf "%s" "${DATE_FIRST_CYCL}" | \
-                sed -n -r -e "s/^([0-9]{8})$/\1/p" )
+                $SED -n -r -e "s/^([0-9]{8})$/\1/p" )
 if [ -z "${DATE_OR_NULL}" ]; then
   print_err_msg_exit "\
 DATE_FIRST_CYCL must be a string consisting of exactly 8 digits of the 
@@ -551,7 +577,7 @@ month, and DD is the 2-digit day-of-month.
 fi
 
 DATE_OR_NULL=$( printf "%s" "${DATE_LAST_CYCL}" | \
-                sed -n -r -e "s/^([0-9]{8})$/\1/p" )
+                $SED -n -r -e "s/^([0-9]{8})$/\1/p" )
 if [ -z "${DATE_OR_NULL}" ]; then
   print_err_msg_exit "\
 DATE_LAST_CYCL must be a string consisting of exactly 8 digits of the 
@@ -573,7 +599,7 @@ CYCL_HRS_str="( $CYCL_HRS_str)"
 i=0
 for CYCL in "${CYCL_HRS[@]}"; do
 
-  CYCL_OR_NULL=$( printf "%s" "$CYCL" | sed -n -r -e "s/^([0-9]{2})$/\1/p" )
+  CYCL_OR_NULL=$( printf "%s" "$CYCL" | $SED -n -r -e "s/^([0-9]{2})$/\1/p" )
 
   if [ -z "${CYCL_OR_NULL}" ]; then
     print_err_msg_exit "\
@@ -732,13 +758,15 @@ case $MACHINE in
     ;;
 
   *)
-    print_err_msg_exit "\
+  if [ -z "$FIXgsm" -o -z "$TOPO_DIR" -o -z "$SFC_CLIMO_INPUT_DIR" ]; then 
+      print_err_msg_exit "\
 One or more fix file directories have not been specified for this machine:
   MACHINE = \"$MACHINE\"
   FIXgsm = \"${FIXgsm:-\"\"}
   TOPO_DIR = \"${TOPO_DIR:-\"\"}
   SFC_CLIMO_INPUT_DIR = \"${SFC_CLIMO_INPUT_DIR:-\"\"}
 You can specify the missing location(s) in config.sh"
+  fi
     ;;
 
 esac
@@ -755,7 +783,7 @@ esac
 #
 #-----------------------------------------------------------------------
 #
-mng_extrns_cfg_fn=$( readlink -f "${SR_WX_APP_TOP_DIR}/Externals.cfg" )
+mng_extrns_cfg_fn=$( $READLINK -f "${SR_WX_APP_TOP_DIR}/Externals.cfg" )
 property_name="local_path"
 #
 # Get the base directory of the FV3 forecast model code.
@@ -827,7 +855,7 @@ check_var_valid_value \
 # Set USE_CUSTOM_POST_CONFIG_FILE to either "TRUE" or "FALSE" so we don't
 # have to consider other valid values later on.
 #
-USE_CUSTOM_POST_CONFIG_FILE=${USE_CUSTOM_POST_CONFIG_FILE^^}
+USE_CUSTOM_POST_CONFIG_FILE=$(echo_uppercase $USE_CUSTOM_POST_CONFIG_FILE)
 if [ "$USE_CUSTOM_POST_CONFIG_FILE" = "TRUE" ] || \
    [ "$USE_CUSTOM_POST_CONFIG_FILE" = "YES" ]; then
   USE_CUSTOM_POST_CONFIG_FILE="TRUE"
@@ -991,7 +1019,7 @@ fi
 if [ "${EXPT_BASEDIR:0:1}" != "/" ]; then
   EXPT_BASEDIR="${SR_WX_APP_TOP_DIR}/../expt_dirs/${EXPT_BASEDIR}"
 fi
-EXPT_BASEDIR="$( readlink -m ${EXPT_BASEDIR} )"
+EXPT_BASEDIR="$( $READLINK -m ${EXPT_BASEDIR} )"
 mkdir_vrfy -p "${EXPT_BASEDIR}"
 #
 #-----------------------------------------------------------------------
@@ -1076,7 +1104,7 @@ if [ "${RUN_ENVIR}" = "nco" ]; then
 # to such a directory.  Resolve any symlinks in the path specified by 
 # FIXam and check that this is the case.
 #
-  path_resolved=$( readlink -m "$FIXam" )
+  path_resolved=$( $READLINK -m "$FIXam" )
   if [ ! -d "${path_resolved}" ]; then
     print_err_msg_exit "\
 In order to be able to generate a forecast experiment in NCO mode (i.e. 
@@ -1099,7 +1127,7 @@ the experiment generation script."
 # symlink to such a directory.  Resolve any symlinks in the path specified
 # by FIXLAM and check that this is the case.
 #
-  path_resolved=$( readlink -m "$FIXLAM" )
+  path_resolved=$( $READLINK -m "$FIXLAM" )
   if [ ! -d "${path_resolved}" ]; then
     print_err_msg_exit "\
 In order to be able to generate a forecast experiment in NCO mode (i.e. 
@@ -1275,7 +1303,7 @@ check_var_valid_value "USE_USER_STAGED_EXTRN_FILES" "valid_vals_USE_USER_STAGED_
 # Set USE_USER_STAGED_EXTRN_FILES to either "TRUE" or "FALSE" so we don't 
 # have to consider other valid values later on.
 #
-USE_USER_STAGED_EXTRN_FILES=${USE_USER_STAGED_EXTRN_FILES^^}
+USE_USER_STAGED_EXTRN_FILES=$(echo_uppercase $USE_USER_STAGED_EXTRN_FILES)
 if [ "${USE_USER_STAGED_EXTRN_FILES}" = "YES" ]; then
   USE_USER_STAGED_EXTRN_FILES="TRUE"
 elif [ "${USE_USER_STAGED_EXTRN_FILES}" = "NO" ]; then
@@ -1322,7 +1350,7 @@ check_var_valid_value "DO_ENSEMBLE" "valid_vals_DO_ENSEMBLE"
 # Set DO_ENSEMBLE to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-DO_ENSEMBLE=${DO_ENSEMBLE^^}
+DO_ENSEMBLE=$(echo_uppercase $DO_ENSEMBLE)
 if [ "$DO_ENSEMBLE" = "TRUE" ] || \
    [ "$DO_ENSEMBLE" = "YES" ]; then
   DO_ENSEMBLE="TRUE"
@@ -1788,7 +1816,7 @@ pattern glob_pattern:
 
   fn=$( ls -1 ${glob_pattern} )
   RES_IN_FIXLAM_FILENAMES=$( \
-    printf "%s" $fn | sed -n -r -e "s/^C([0-9]*)$suffix/\1/p" )
+    printf "%s" $fn | $SED -n -r -e "s/^C([0-9]*)$suffix/\1/p" )
   if [ "${GRID_GEN_METHOD}" = "GFDLgrid" ] && \
      [ "${GFDLgrid_RES}" -ne "${RES_IN_FIXLAM_FILENAMES}" ]; then
     print_err_msg_exit "\
@@ -1918,7 +1946,7 @@ check_var_valid_value "QUILTING" "valid_vals_QUILTING"
 # Set QUILTING to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-QUILTING=${QUILTING^^}
+QUILTING=$(echo_uppercase $QUILTING)
 if [ "$QUILTING" = "TRUE" ] || \
    [ "$QUILTING" = "YES" ]; then
   QUILTING="TRUE"
@@ -1938,7 +1966,7 @@ check_var_valid_value "PRINT_ESMF" "valid_vals_PRINT_ESMF"
 # Set PRINT_ESMF to either "TRUE" or "FALSE" so we don't have to consider
 # other valid values later on.
 #
-PRINT_ESMF=${PRINT_ESMF^^}
+PRINT_ESMF=$(echo_uppercase $PRINT_ESMF)
 if [ "${PRINT_ESMF}" = "TRUE" ] || \
    [ "${PRINT_ESMF}" = "YES" ]; then
   PRINT_ESMF="TRUE"
@@ -2008,15 +2036,14 @@ NNODES_RUN_FCST=$(( (PE_MEMBER01 + PPN_RUN_FCST - 1)/PPN_RUN_FCST ))
 #-----------------------------------------------------------------------
 #
 # Create a new experiment directory.  Note that at this point we are 
-# guaranteed that there is no preexisting experiment directory.
+# guaranteed that there is no preexisting experiment directory. For
+# platforms with no workflow manager, we need to create LOGDIR as well,
+# since it won't be created later at runtime.
 #
 #-----------------------------------------------------------------------
 #
 mkdir_vrfy -p "$EXPTDIR"
-
-
-
-
+mkdir_vrfy -p "$LOGDIR"
 
 
 
@@ -2078,7 +2105,7 @@ cp_vrfy $USHDIR/${EXPT_DEFAULT_CONFIG_FN} ${GLOBAL_VAR_DEFNS_FP}
 #
 
 # Read all lines of GLOBAL_VAR_DEFNS file into the variable line_list.
-line_list=$( sed -r -e "s/(.*)/\1/g" ${GLOBAL_VAR_DEFNS_FP} )
+line_list=$( $SED -r -e "s/(.*)/\1/g" ${GLOBAL_VAR_DEFNS_FP} )
 #
 # Loop through the lines in line_list and concatenate lines ending with
 # the line bash continuation character "\".
@@ -2119,7 +2146,7 @@ done <<< "${line_list}"
 #-----------------------------------------------------------------------
 #
 # Also should remove trailing whitespace...
-line_list=$( sed -r \
+line_list=$( $SED -r \
              -e "s/^([ ]*)([^ ]+.*)/\2/g" \
              -e "/^#.*/d" \
              -e "/^$/d" \
@@ -2165,7 +2192,7 @@ str_to_insert=${str_to_insert//$'\n'/\\n}
 # the string "#!", e.g. "#!/bin/bash").
 #
 regexp="(^#!.*)"
-sed -i -r -e "s|$regexp|\1\n\n${str_to_insert}\n|g" ${GLOBAL_VAR_DEFNS_FP}
+$SED -i -r -e "s|$regexp|\1\n\n${str_to_insert}\n|g" ${GLOBAL_VAR_DEFNS_FP}
 
 
 
@@ -2185,7 +2212,7 @@ while read crnt_line; do
 # or more characters representing the value that the variable is being
 # set to.
 #
-  var_name=$( printf "%s" "${crnt_line}" | sed -n -r -e "s/^([^ ]*)=.*/\1/p" )
+  var_name=$( printf "%s" "${crnt_line}" | $SED -n -r -e "s/^([^ ]*)=.*/\1/p" )
 #echo
 #echo "============================"
 #printf "%s\n" "var_name = \"${var_name}\""
@@ -2390,7 +2417,7 @@ FV3_NML_ENSMEM_FPS=( $( printf "\"%s\" " "${FV3_NML_ENSMEM_FPS[@]}" ))
 GLOBAL_VAR_DEFNS_FP="${GLOBAL_VAR_DEFNS_FP}"
 # Try this at some point instead of hard-coding it as above; it's a more
 # flexible approach (if it works).
-#GLOBAL_VAR_DEFNS_FP=$( readlink -f "${BASH_SOURCE[0]}" )
+# GLOBAL_VAR_DEFNS_FP=$( $READLINK -f "${BASH_SOURCE[0]}" )
 
 DATA_TABLE_TMPL_FN="${DATA_TABLE_TMPL_FN}"
 DIAG_TABLE_TMPL_FN="${DIAG_TABLE_TMPL_FN}"
@@ -2601,6 +2628,7 @@ FVCOM_FILE="${FVCOM_FILE}"
 #
 NCORES_PER_NODE="${NCORES_PER_NODE}"
 PE_MEMBER01="${PE_MEMBER01}"
+RUN_CMD_FCST="${RUN_CMD_FCST}"
 EOM
 } || print_err_msg_exit "\
 Heredoc (cat) command to append new variable definitions to variable 
diff --git a/ush/source_util_funcs.sh b/ush/source_util_funcs.sh
index 1ebe07aff..1b63ade7b 100644
--- a/ush/source_util_funcs.sh
+++ b/ush/source_util_funcs.sh
@@ -8,7 +8,11 @@ function source_util_funcs() {
 #
 #-----------------------------------------------------------------------
 #
-  local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  if [[ $(uname -s) == Darwin ]]; then
+    local scrfunc_fp=$( greadlink -f "${BASH_SOURCE[0]}" )
+  else
+    local scrfunc_fp=$( readlink -f "${BASH_SOURCE[0]}" )
+  fi
   local scrfunc_fn=$( basename "${scrfunc_fp}" )
   local scrfunc_dir=$( dirname "${scrfunc_fp}" )
 #
@@ -40,6 +44,15 @@ function source_util_funcs() {
 #
 #-----------------------------------------------------------------------
 #
+# Source the file that defines MacOS-specific UNIX command-line
+# utilities, that mimic the functionality of the GNU equivalents
+#
+#-----------------------------------------------------------------------
+#
+  . ${bashutils_dir}/define_macos_utilities.sh
+#
+#-----------------------------------------------------------------------
+#
 # Source the file containing the functions that print out messages.
 #
 #-----------------------------------------------------------------------
@@ -74,6 +87,15 @@ function source_util_funcs() {
 #
 #-----------------------------------------------------------------------
 #
+# Source the file containing the functions that will echo given strings
+# as uppercase or lowercase
+#
+#-----------------------------------------------------------------------
+#
+  . ${bashutils_dir}/change_case.sh
+#
+#-----------------------------------------------------------------------
+#
 # Source the file containing the function that checks for preexisting 
 # directories or files and handles them according to a specified method
 # (which can be one of "delete", "rename", and "quit").
diff --git a/ush/valid_param_vals.sh b/ush/valid_param_vals.sh
index d837796a9..ec9f4178e 100644
--- a/ush/valid_param_vals.sh
+++ b/ush/valid_param_vals.sh
@@ -1,7 +1,8 @@
 valid_vals_RUN_ENVIR=("nco" "community")
 valid_vals_VERBOSE=("TRUE" "true" "YES" "yes" "FALSE" "false" "NO" "no")
-valid_vals_MACHINE=("WCOSS_CRAY" "WCOSS_DELL_P3" "HERA" "ORION" "JET" "ODIN" "CHEYENNE" "STAMPEDE" "GAEA")
+valid_vals_MACHINE=("WCOSS_CRAY" "WCOSS_DELL_P3" "HERA" "ORION" "JET" "ODIN" "CHEYENNE" "STAMPEDE" "GAEA" "MACOS" "LINUX")
 valid_vals_SCHED=("slurm" "pbspro" "lsf" "lsfcray" "none")
+valid_vals_WORKFLOW_MANAGER=("rocoto" "none")
 valid_vals_PREDEF_GRID_NAME=( \
 "RRFS_CONUS_25km" \
 "RRFS_CONUS_13km" \