Add correction to the NCEP 1/12 degree grid (rtg sst .083 deg data) in grib2.
This correction was in rd_grib1.F, but was more difficult in rd_grib2.F since
grib2 files don't have a grid number.
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.
git-svn-id: https://svn-wrf-wps.cgd.ucar.edu/trunk@572 86b71a92-4018-0410-97f8-d555beccfc3a