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(RESOLVED) Trouble ungribbing dataset ds627.0

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Ren JY

New member
I have met some trouble ungribing the dataset ds627.0 downloaded from
The problem is I don't know how to treat with the two kinds of pressure-level files,****** and******. I tried to ungrib them together with [prefix = 'FILE'] in namelist.wps, but several mistakes occured when I ran the real.exe. I also tried to ungrib sc&uv files individually, setting [prefix = '3D'] and [prefix = 'SFC'] (I know it works if you download ERA-Interim high level&surface data from, and still failed.
I would be appreciate if you give me some advice or sth like a userguidebook link. FYI, I'm working on WRF v3.5, CentOS 7.
I have moved this post to the ungrib section of the forum, as it's more appropriate here. Someone will respond to your post soon.
kwerner said:
I have moved this post to the ungrib section of the forum, as it's more appropriate here. Someone will respond to your post soon.

Just noticed and edited my diction. Thank you very much:)
Take a look at this section of the WRF Users' Guide:

This should explain the process for using 2 different data sources (which although both types are ERA-Interim, the method still applies). Basically you will need to go through the process of ungrib twice (once for the surface data, and once for the atmospheric data), and should end up with intermediate files with 2 different prefixes. After that, you will use both prefixes to run metgrid once. The Users' Guide chapter will explain in detail.

When ungribbing this particular dataset, you should be using to link to the WPS/ directory as "Vtable."

If you are still having trouble, please attach the following files:
1) namelist.wps, namelist.input
2) one of each type of your data input files for the initial time (1 sfc file, 1 3D file)
3) geogrid.log, ungrib.log, metgrid.log
4) real.exe log

Hi Kelly,
Sorry for my late reply. These days I repeated ungribbing the two types of ERA-Interim files and still got stuck in real.exe. I'm quite sure I linked the I ungribbed the 'sc' files with 'prefix = 3D', and the 'uv' files with 'prefix = SFC'. The metgrid.exe could run successfully, but by using 'ncdump -h', I noticed the met_em files have no soil level(NUM_METGRID_SOIL_LEVELS = 0). Normally the value should be 4, according to other people's results. I don't know if that matters. Maybe you or someone could help me figure out it. Thanks!


  • namelist.wps
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  • ungrib.log
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  • namelist.input
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  • rsl.error.0000.log
    2.3 KB · Views: 62
Based on your ungrib.log file, it looks like you are only processing the variables UU and VV for every time step. So it seems that you are missing a lot of input data. Take a look at this FAQ that shows the mandatory fields for running WRF:

You need to make sure that you have all of those prior to running ungrib.

Hi Kelly,
Finally I solved my problem. The "sc/uv" doesn't matter actually, since they are named after "*". They shall both be ungribbed with prefix "3D", and surface data "*" must be linked through link.csh with prefix "SFC". Thank you a lot for your concern and support.

I'm glad to hear that you were able to solve this! Thank you for updating the post.