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• -w key[:{s|d|i}]{=|!=}value,key[:{s|d|i}]=value,...: a 'Where' clause. Only GRIB messages matching the key/value constraints are copied to the output file. A valid constraint is of type key=value or key!=value. For each key a string (key:s), a double (key:d) or an integer (key:i) type can be defined. Default type is string. In the value, you can also use the forward-slash character '/' to specify an OR condition (i.e. a logical disjunction). Note: only one -w clause is allowed.
• -p key[:{s|d|i}],key[:{s|d|i}],..: declaration of keys to print. For each key a string (key:s), a double (key:d) or an integer (key:i) type can be requested. Default type is string.

Processing data - recipes

In order to process ECMWF Model level data, additional steps are required but there are recipes already available on-line e.g.:

1. By converting parameters on model levels to GRIB1
   https://medium.com/@valcap74/how-to-run-wrf-model-driven-by-era5-on-model-levels-3c3e31838d22
   https://confluence.ecmwf.int/display/OIFSUF/Grib+to+Netcdf+conversion
2. Directly from GRIB2 with an external Vtable exclusively from ML in GRIB2: https://earthscience.stackexchange.com/questions/9497/running-wrf-with-ecmwf-grib2-model-levels
   Since wgrib has separate executables for GRIB1 and GRIB2, wgrib and therefore WPS cannot process mixed files containing GRIB1 and GRIB2. Therefore it is required to have ML data (GRIB2) and SFC data (GRIB1) is separate files and to un ungrib independently for GRIB1 and again for GRIB2 before running metgrid. It is required to make following changes in namelist.wps between two ungrib runs:

&ungrib
 prefix = 'SFILE' 
&ungrib
  prefix = 'MFILE'

To ensure that the two ungrib runs do not overwrite each other.
Then in metgrid section of namelist.wps you need to make sure to use both files created by ungrib runs:

 &metgrid
 fg_name = 'SFILE' 'MFILE' 

What has changed since these recipes are written is that now some GRIB2 parameters are compressed using CCSDS compression which WRF Pre-Processing System cannot decode. Consequently, CCSDS packing in GRIB2 has to be changed to SIMPLE PACKING before any of these steps with:

grib_set -r -w packingType=grid_ccsds -s packingType=grid_simple ccsds.grib grid_simple.grib 

Product description

The products are High-Resolution (HRES) forecast and analysis data with a 0.1° by 0.1° grid (a subset of ECMWF Set-I).

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