WRF Preprocessing System Known Problems and Fixes

Version 2.2.1 of the WRF Pre-Processing System (WPS) was released on October 31, 2007.

WPS Version 2.2.1

Vtable for GFS and NAM Data Updated (posted 1/28/08)

Problem: The grib 2 codes for PMSL and SOILHGT have been updated in Vtable.NAM to match the data in grib 1 files. The grib 2 code for SOILHGT has been updated in Vtable.GFS to match that in grib 1 file. If SOILGHT is missing, the skin temperature, soil temperature and lowest model level temperature could be different from that obtained from grib 1 data.

Solution: Get the updated Vtables (Vtable.NAM, Vtable.GFS), and replace the ones in WPS/ungrib/Variable_Tables/ directory.

Wind Rotation Error for some Dataset (posted 12/6/07)

Problem: A bug is uncovered that affects only the wind U and V fields for ARW domains that use source data having wind fields that are not given as true, earth-relative winds. Examples of such sources include NAM and RUC data. Essentially, the wind rotation code was incorrectly re-computing the rotation angle when rotating grid-relative winds to earth-relative winds because some code wasn't properly placed within an if-test. If you are not sure whether the bug affects you, check metgrid.log file to see if there are messages about "Rotating map winds to earth winds". If so, the winds on ARW grid would be wrong.

All NMM domains, and those ARW domains using source data with earth-relative wind (e.g., GFS) are not affected by this bug. This bug only appeared in 2.2.1, and does not affect version 2.2 of the WPS.

Solution: Get the updated WPS tar file, or get the file that fixes the bug: rotate_winds_module.f90.fix. Place the modified file in WPS/metgrid/src/ directory, rename it to rotate_winds_module.f90. Recompile.