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Is WRF output grid exactly the same as WPS grid?


New member

The WPS domain I get when using plotgrids_new.ncl and plotgrids_old.ncl (see "WPS_50km.png" attached) is somewhat different from the domain of my WRF output (see "WRF_50km.png" attached). I used wrf python to plot the simulation output. I have also plotted the data with ncl (see "WRFplot_tfDoNDCOverlay_False" attached), using wrf_map_resources and gsn_csm_contour_map. In this latter image, the map domain is similar to that of WPS, but the domain covered by the output is not the same, so I am confused...

In my WRF and WPS namelists, e_we, e_sn, dx and dy are the same. Shouldn't the WRF domain be exactly the same as the WPS domain?

Thanks in advance,



  • WPS_50km.png
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  • WRF_50km.png
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  • WRFplot_tfDoNDCOverlay_False.png
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The difference you're seeing could be specific to the map projection you're using. Can you first try to look at the domains with 'ncview?' You can look at the met_em.d01* files and then compare those to the wrfout* files. If that doesn't help you, can you please attach your namelist.wps file so I can see what domain settings you're using? Thanks!

I checked the met_em.d01* files and the wrfout* files, and they show the same domain as the one I get with wrf python. This domain is not the same as the one shown with plotgrids_new.ncl and plotgrids_old.ncl. It seems to me that the ncl functions that plot WRF output do not correctly show the domain of the polar stereographic projections (I also plotted the domain of another wrf simulation with a polar stereographic projection and I had the same issue).

I send you attached the namelist.wps file.

I think this thread may now be more appropriate for the post-processing tools forum, so feel free to move this to that forum if you want.

Thank you for your help,



  • namelist.wps.txt
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Hi Marta,

Yes, I think you may be right. We are aware that the plotgrids*.ncl programs do not work properly on some map projections. Are you able to move forward with your study using the domains that you get when you plot with python (the domains shown in the wrf output)?
Hi kwerner,

Yes, wrf-python works well, so I can plot my domain.

Thanks for your help.