WRF-NMM Users Page

WRF Modeling System Known Problems and Fixes

WRF Version 3.2 was released on April 2, 2010.

WRF Version 3.2

Uninitialized Variable Problem (posted 5/5/10)

Problem: A problem with potentially uninitialized ProcOrient field in linked lists of state variables is uncovered in v3.2. This could lead to sporadic hanging of MPI jobs.

Solution: Download the revised gen_allocs.c file and replace the same file in WRFV3/tools/. Do a full recompile, beginning with 'clean -a'.

Problem when Compiling/Running with gfortran (posted 4/23/10)

Problem: Depending on the version of gfortran/gcc libraries used a compile-time or run-time problem may be encountered.

Solution: Download the tar file and unpack it at the same level as your WRFV3 directory to overwrite the old programs. Do a clean, reconfigure, and recompile.

Additional namelist Required To Specify IO Format Option (posted 4/20/10)

Problem: Due to expanded IO capability in V3.2 (runtime IO and increased IO streams), several runtime options require additional namelist variables, including:

sst_update: Requires io_form_auxinput4 = 2 in &time_control

Other namelists like io_form_history, io_form_input, io_form_boundary and io_form_restart are also required in the namelist.input.

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.

Possible Performance Hit with V3.2 code (Posted 4/2/10)

Problem 1: Two fixes introduced in V3.2 may result in performance hit. One of them is the change for RRTM longwave radiation option. Since the fix involves adding model layers above model top, the lower the model top (p_top), the more likely to see a slow down.

Solution: One solution is to increase the time interval to call the scheme hence maintain the same wallclock time. The other solution is to modify phys/module_ra_rrtm.F, line 31, and change layer depth deltap from 4 mb to a larger value. However with larger layer depth, one may not obtain optimal results.

Problem 2: The other performance hit is related to adding semi-lagrangian fall terms in all WSM/WDM schemes. This could affect finer grid model run more.

Compile V3.2 with ifort (posted 4/2/10)

Solution: With the new code, one must ust at least ifort 10 to compile