Hi Natalia,
The default output file format (wrfout files) has changed starting with WRF version 4.0 and now uses netCDF4 compression which is not supported by CALWRF.
In your WRF namelist file, you can use the option “use_netcdf_classic = .true.” in the &time_control section so that the wrfout files will be recognized by CALWRF.
Already compressed WRF output files can also be converted to the classic format by using nccopy.
Hope this will help.
Hugo Beaumont