diff --git a/ush/get_extrn_mdl_files.sh b/ush/get_extrn_mdl_files.sh
index e5287fae6..5b6c337ed 100755
--- a/ush/get_extrn_mdl_files.sh
+++ b/ush/get_extrn_mdl_files.sh
@@ -105,30 +105,30 @@ Could not change directory to EXTRN_MDL_FILES_DIR:
 #
 #-----------------------------------------------------------------------
 #
+EXTRN_MDL_INFO_FP="${EXTRN_MDL_FILES_DIR}/${EXTRN_MDL_INFO_FN}"
 
-#if [ -f "${EXTRN_MDL_INFO_FN}" ]; then
+#if [ -f "${EXTRN_MDL_INFO_FP}" ]; then
 #  print_err_msg_exit "\
-#File defining external model parameters (EXTRN_MDL_INFO_FN) already ex-
+#File defining external model parameters (EXTRN_MDL_INFO_FP) already ex-
 #ists in directory EXTRN_MDL_FILES_DIR:
 #  EXTRN_MDL_FILES_DIR = \"${EXTRN_MDL_FILES_DIR}\"
-#  EXTRN_MDL_INFO_FN = \"${EXTRN_MDL_INFO_FN}\"
+#  EXTRN_MDL_INFO_FP = \"${EXTRN_MDL_INFO_FP}\"
 #"
 #else
   get_extrn_mdl_file_dir_info \
     "$EXTRN_MDL_NAME" "$ANL_OR_FCST" "$CDATE" "$TIME_OFFSET_HRS" \
-    "$EXTRN_MDL_INFO_FN" ${EXTRN_MDL_INFO_VAR_NAMES[@]}
+    "$EXTRN_MDL_INFO_FP" ${EXTRN_MDL_INFO_VAR_NAMES[@]}
 #fi
 
 
-if [ ! -f "${EXTRN_MDL_INFO_FN}" ]; then
+if [ ! -f "${EXTRN_MDL_INFO_FP}" ]; then
   print_err_msg_exit "\
-File defining external model parameters (EXTRN_MDL_INFO_FN) does not ex-
-ist in directory EXTRN_MDL_FILES_DIR:
-  EXTRN_MDL_FILES_DIR = \"${EXTRN_MDL_FILES_DIR}\"
-  EXTRN_MDL_INFO_FN = \"${EXTRN_MDL_INFO_FN}\"
+File defining external model parameters (EXTRN_MDL_INFO_FP) does not ex-
+ist:
+  EXTRN_MDL_INFO_FP = \"${EXTRN_MDL_INFO_FP}\"
 "
 else
-  . ${EXTRN_MDL_INFO_FN}
+  . ${EXTRN_MDL_INFO_FP}
 fi
 #
 # As a check, print out the variables and their values set by the above 
diff --git a/ush/setup.sh b/ush/setup.sh
index adbaad3a9..a10b386c5 100755
--- a/ush/setup.sh
+++ b/ush/setup.sh
@@ -234,7 +234,21 @@ predef_domain must be set either to an empty string or to one of the following:
 fi
 
 
-
+#
+#-----------------------------------------------------------------------
+#
+# Make sure that preexisting_dir_method is set to a valid value.
+#
+#-----------------------------------------------------------------------
+#
+iselementof "$preexisting_dir_method" valid_vals_preexisting_dir_method || { \
+valid_vals_preexisting_dir_method_str=$(printf "\"%s\" " "${valid_vals_preexisting_dir_method[@]}");
+print_err_msg_exit "\
+Value specified in preexisting_dir_method is not supported:
+  preexisting_dir_method = \"$preexisting_dir_method\"
+preexisting_dir_method must be set to one of the following:
+  $valid_vals_preexisting_dir_method_str
+"; }
 #
 #-----------------------------------------------------------------------
 #
diff --git a/ush/valid_param_vals.sh b/ush/valid_param_vals.sh
index bb00680af..7eb4f4db3 100644
--- a/ush/valid_param_vals.sh
+++ b/ush/valid_param_vals.sh
@@ -7,3 +7,4 @@ valid_vals_RES=("48" "96" "192" "384" "768" "1152" "3072")
 valid_vals_EXTRN_MDL_NAME_ICSSURF=("GFS" "RAPX" "HRRRX")
 valid_vals_EXTRN_MDL_NAME_LBCS=("GFS" "RAPX" "HRRRX")
 valid_vals_grid_gen_method=("GFDLgrid" "JPgrid")
+valid_vals_preexisting_dir_method=("delete" "rename" "quit")