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(RESOLVED) Using ECMWF data: Error in ext_pkg_write_field

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To run WRF with ECMWF data I need to download the data of the model levels and surface separately. Afterwards, run ungrib separately, where the 'prefix' in namelist.wps need to named differently before each time. However, it isn't stop here. We need the geopotential/pressure data .According to these following links:

The process in both links is quit clear and similar, but the difference between them is that the first one doesn't need geopotential data (see the model levels Vtable inside the link) and the second one requires it. In addition, the first one based on ERA-5 data, and the second one based on ECMWF data.
So, I used the ECMWF data, there fore used the Vtables from the second link, and did the whole process.
One problem is that: the geopotential data is needed to be calculated - so I did according to following link:
I downloaded 'fc' (forecast) data and not 'an' (analysis) - so I just changed that, but from some reason this isn't can be done..? why is that? when I changed back to 'an' - I could download the data but just only every 6 hours step..why is that happen too?

So I decided, just to see if everything works, to download the data every 6 hours step. And, I back to the technical process and typed the command: ./util/calc_ecmwf_p.exe
At this running - I got warnings that say: ''Warning TT and SPECHUMD not found. No RH will be computed'. I moved on to run metgrid and I got the error: 'Error in ext_pkg_write_field' . I went inside to metgrid.log file and I saw that I don't have data from model level 1 until 69 - which is OK because I didn't download this data - these levels are not necessary to run WRF (or maybe not?) anyways - I will appreciate your help!

See attached the print screens of the the warnings and error + metgrid.log file.

Thank you very much,


  • Error when run metgrid_photo_one.jpg
    Error when run metgrid_photo_one.jpg
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  • Error when run metgrid_photo_two_endOfMetgrid.jpg
    Error when run metgrid_photo_two_endOfMetgrid.jpg
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  • metgrid.log
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  • Warnings alerts after calc ecmwf pressure.jpg
    Warnings alerts after calc ecmwf pressure.jpg
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As for the questions regarding the different web links, I am unable to comment on those, as they are not websites that we support here at NCAR. I am not sure why you were having difficulties downloading the data.

The error message "Error in ext_pkg_write_field" often indicates that surface data is missing. You will need the surface and lower levels to be able to run metgrid, real, and wrf. If you do have the surface data, then the error message is likely due to the missing bottom 69 levels of data.