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WRF Restart Runs Fail When Mosaic Land Use Tiling Is On


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I am attempting to run nested (9km x 3km x 1km) urban simulations with the use of the mosaic landuse categories option. The simulation is stable and the output is realistic when I initialize and integrate the model forward in time. However, whenever my compute limit is reached and I restart the run, it fails after a few time steps (it does not matter if the run is restarted towards the beginning middle or end of the simulation). After some testing, I learned that the mosaic tiling (sf_surface_mosaic) option is the causing the problem. When the mosaic option is turned off during the restart run, the model runs without any issue. Unfortunately, this is not a viable solution because my tests show that turning off the mosaic during a restart changes the output values.

The rsl.error file indicates that the model initially expereiences numerous cfl errors when the mosaic is on. These cfl erros lead to segmentation faults when the radiation is called, and this causes the model to fail. Perhaps the mosaic option is trying to create a secondary mosaic and this is causing errors?

Any help that can be provided will be appreciated. Example restart files, my namelist (before restarting), and the rsl.error file are linked or attached to this post, and a brief synopsis of my setup is listed below:

Link to restart files via Nextcloud:

WRF = version 4.4.2
LSM = Noah
Landuse/Landcover = NLCD (default 9s)
SST_update = on
UCM = single layer
sf_surface_mosaic = 1 (mosaic on)
mosaic_cat = 6

Thank you in advance,


  • rsl.error.0000.txt
    15.6 KB · Views: 5
  • namelist.input.txt
    4.5 KB · Views: 14
I am still working on this, but I would like to share some information I have found regarding this issue.

It seems as though a similar issue was reported as a bug on Github at the beginning of 2022, and the fix was eventually accepted by the developers. Essentially, there was a run-time issue that prevented WRF from running with the mosaic option on and the WUDAPT option off. However, it is possible that the updated code does not apply to restart runs.