WRF Preprocessing System Version 3.2: Known Problems and Fixes

Known Problems in Version 3.2 and 3.2.1

Problem: There is a processing error in degribing grib 2 NCEP 1/12 degree SST data (rtg sst 0.083 degree data). The difference errors (.08333333 - .083) accumulate from west to east so the error is about 1.5 degrees longitude at 359 deg east. The sst errors are significant along the east and west coasts of the U.S. as well as in the Great Lakes. If you have this data in grib 1 format, it is fine.

Solution: Download the modified rd_grib2.F to WPS/ungrib/src.

PROBLEM USING GFS REAL-TIME DATA SINCE MAY 22, 2012:

Problem: NCEP has updated its real-time GFS GRIB2 files, beginning 2012-05-22_12:00:00. This is causing ungrib to extract incorrect data for surface fields. If your domain includes a pole or the Prime Meridian (0° longitude), program real may abort. If your domain lies elsewhere, the real program may not abort, but you will likely get incorrect surface fields.

Solution: You need to go into the /WPS/ungrib/src/rd_grib2.F file and search for these lines:

elseif(gfld%ipdtmpl(10).eq.101) then
! MSL
level=201300.

Below that, you will need to add the following:
elseif(gfld%ipdtmpl(10).eq.103) then
! Height above ground (m)
if ( (gfld%ipdtmpl(12) .eq. 2. ) .or.
& (gfld%ipdtmpl(12) .eq. 10.) ) then
level=200100.
else
cycle MATCH_LOOP
endif

Once you add this, save the file and recompile WPS. There is no need to perform a 'clean -a' or to reconfigure.