Handle empty track files in get_storm_ids.

Do not open or analyze empty storm track files (.tcst files).  Instead,
return an empty list.

Also fixed typo/bug, logger was incorrectly referenced as log instead of
logger.

ush/met_util.py

@@ -247,6 +247,12 @@ def get_storm_ids(filter_filename, logger):
     cur_filename = sys._getframe().f_code.co_filename
     cur_function = sys._getframe().f_code.co_name
     storm_id_list = set()
+    empty_list = [] 
+
+    # Check if the filter_filename is empty, if it
+    # is, then return.  
+    if os.stat(filter_filename).st_size == 0:
+         return empty_list
     with open(filter_filename) as fileobj:
          # skip the first line as it contains the header
          next(fileobj)
@@ -444,7 +450,7 @@ def retrieve_and_regrid(tmp_filename, cur_init, cur_storm, out_dir, logger, p):
     cur_filename = sys._getframe().f_code.co_filename
     cur_function = sys._getframe().f_code.co_name
     gfs_dir = p.opt["GFS_DIR"]
-    regrid_data_plane_exe = p.opt["REGRID_DATA_PLANE"]
+    regrid_data_plane_exe = p.opt["REGRID_DATA_PLANE_EXE"]
     wgrib2_exe = p.opt["WGRIB2"]
     egrep_exe = p.opt["EGREP_EXE"]
 
@@ -968,7 +974,7 @@ def prune_empty(output_dir, p, logger):
                        "Empty file: " + file +
                        "...removing" )
 
-                log.info(msg)
+                logger.info(msg)
                 os.remove(file)