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Dear WRF users

I am using WRF version 4.0 and I am trying different PBL schemes. All of the schemes work except for QNSE scheme. The model crashes with a segmentation fault error when the radiation scheme is called. Seems like no issue with the radiation scheme, but more likely, that’s where the error gets picked up. I noted that whichever radiation scheme (lw/sw) or microphysics scheme I use, the length of the simulation always is equal to the value I set for “radt” in the namelist.input. Also tried with both with ERA5 and NCEP data reanalysis data but it didnt work. Also tried lower Fortran optimization, -O2 or -O1 rather than -O3 but nothing seem to work. I am attaching the recent namelist.input to this post.
I would be grateful if someone can point me to the error.


  • namelist.txt
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The namelist looks fine except that the cumulus scheme should be turned on for the 18km domain, i.e.,
cu_physics = 1, 0, 0,

You can also set a larger time step, i..e,
time_step = 72 (or 90)

Also, this is a triply-nested case, which makes it hard to debug what is wrong. I wonder whether you can run this case over a single domain (i.e., max_dom=1) ? This will help us to narrow down possible issues.

Since the grid number is pretty small (50 x 50), I suggest you run this case with no more than 4 processors.
Thanks for your prompt response. I have submitted the runs with the options you have provided.
Do you mean to only use 4 processors from a single node ? I am currently using the following

SBATCH --ntasks=96
SBATCH --ntasks-per-node=24
SBATCH --time=00:30:00

This allows me to select 4 nodes with 24 tasks per node.
Please see the rsl.error files for each of the options used above. None of them worked for me.


  • rsl.error_single_domain.0000
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  • rsl.error_time_step_90.0000
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  • rsl.error_time_step72.0000
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The number of processors are too large for this case. You may need to run with a single node and use only 4 processors out of the 24.
With such a large number of processors you are using at present, domain decomposition would be wrong.
I reduced to 4 processors but I still see the same problem. I am not sure about the issue
Where you able to solve the issue?
I am facing the same error. Model is working fine for all other pbl_schemes except QNSE.

I gives a segmentation error after a few time steps.
I am attaching the namelist and rsl error log.

Looking forward to any kind of help.


  • namelist.input
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  • rsl.error.0000
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  • rsl.out.0000
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No sorry was still not able to resolve the problem.
Probably Jimmy Dudhia can help us out here. I think it has something to do with its link to the radiation schemes and with the landsurface model. But not sure