WRF Preprocessing System Known Problems and Fixes
Version 3.2 of the WRF Pre-Processing System (WPS) was released on April 2, 2010. Version 3.2.1 was release on August 18, 2010.
WPS Version 3.2 and 3.2.1
Processing Error with NCEP SST GRIB2 data
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.