WRF-NMM Users Page

WRF Modeling System Known Problems and Fixes

WRF Version 3.2.1 was released on August 18, 2010.

WRF Version 3.2.1

Thompson Microphysics Scheme (posted 12/14/10)

Problem: WRF Versions 3.2 and 3.2.1 contain a MAJOR bug in the Thompson et al microphysics option number 8 (mp_physics = 8). The bug applies for ALL simulations using this option but is worst for high resolution convective cases because it involves the production of graupel from rain and snow collisions. Any users of this scheme should not trust the results of simulations using these code versions because, instead of creating graupel due to rain/snow collisions, the bug was causing the removal of graupel. This bug is NOT found in earlier versions of WRF.

Besides the bug fix for graupel, other changes have been made to the scheme including a more subtle bug related to rain evaporation that has existed in ALL WRF code versions containing the Thompson et al (2008) scheme since late 2006. This bug was minor in comparison but is fixed in the new code. Any users wishing to fix the rain evaporation bug (involves 2 lines of code) in previous WRF versions may contact the author for details to include this change only.

Also, the intended bug fix replacement file contains a new method to determine the graupel Y-intercept parameter as a design change as well as changes to handle mass/number imbalance checks, especially related to sedimentation. The latter changes are better mathematically and should be hardly visible in real simulations, but came about due to testing the sedimentation scheme in isolation from the rest of the code. The bug-fix code should also be released as part of the next standard WRF code release, though further changes are possible between now and Spring 2011.

Solution: Download a new copy of module_mp_thompson.F fix and replace the one in the phys/ directory. Recompile.

Compiling HWRF with gfortran/ifort compilers (posted 8/23/10)

Problem:An error occurs when compiling HWRF with gfortran or ifort compilers

Solution:Download the revised mediation_integrate.F file and replace the same file in WRFV3/share. Do a full recompile, beginning with 'clean -a'.

Running WRF-NMM with MODIS input data (posted 4/2/10)

Problem:When running WRF-NMM with WPS output using MODIS land use data, the model does not actually use the data.

Solution:A solution is being investigated and will be posted here when it is available.