[Wrf-users] trouble with 2-way nest

[mpborkow at ncsu.edu]

I am running a two-way nest, 12km outer domain with a 4km inner domain
using a NARR dataset.  The setup seems to be fine but I am having trouble
with the model run itself.  I do get one ouput file for each domain for
the initialization time only.  The SLP from these output files match up
well with the reanalysis data in some spots, in other spots the SLP seems
very artificial with the isobars looking erratic.  Here is a sampling of
the errors I am getting:

Timing for Writing wrfout_d01_2004-03-16_00:00:00 for domain        1:  
21.71200 elapsed seconds.
Timing for processing lateral boundary for domain        1:    5.28800
elapsed seconds.
 WRF NUMBER OF TILES =   1
         90190  points exceeded cfl in w_damp
(module_big_step_utilities_em.F)
  MAX AT i,j,k:           174           60           30  cfl,w,d(eta)=    
        nan             nan   2.1000000E-02
Timing for Writing wrfout_d02_2004-03-16_00:00:00 for domain        2:  
18.27400 elapsed seconds.
 WRF NUMBER OF TILES =   1
         21257  points exceeded cfl in w_damp
(module_big_step_utilities_em.F)
  MAX AT i,j,k:             5           55           30  cfl,w,d(eta)=    
        nan   3.5428979E-02   2.1000000E-02
         41992  points exceeded cfl in w_damp
(module_big_step_utilities_em.F)
  MAX AT i,j,k:            10           55           30  cfl,w,d(eta)=    
        nan   5.5973802E-02   2.1000000E-02

 -------------- FATAL CALLED ---------------
 FATAL CALLED FROM FILE:  module_cu_kfeta.b  LINE:    2054
 KAIN-FRITSCH, istop=1, diags
 -------------------------------------------
[4] MPI Abort by user Aborting program !
[4] Aborting program!


My first thought was that it was a time step issue, but my time step is
set at 60s for the 12km domain, 20s for the 4km domain.  I did try
reducing them to 48s and 16s, but this did not solve the problem.  Given
the final error, looks like there may be some error with the KAIN-FRITSCH
scheme, which I only have running on the 12km domain.  Does anyone have
any thoughts as to what the problem may be?  Thanks!

-Matt