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GFS Data Changes: 22 March 2021, 12 UTC

Posted: Wed Mar 17, 2021 4:05 pm
by kwerner
As of 12 UTC on 22 March 2021, NCEP has upgraded the GFS to version 16. There should be no impact on the WRF systems, but there will be some logistical changes. The download location will change to:

ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/gfs.ccyymmdd/hh/atmos/

File sizes will increase by 55% as NCEP is adding several more pressure levels, all of which are above 0.7 hPa (and have no impact on WRF forecasts). The new file size will be about 550 MB. The availability of the files will be delayed by 8 to 11 minutes compared to the current run.

No changes should be necessary for running WPS; however, it is important to use the "pmin" variable in the ungrib section of namelist.wps so as not to waste time processing all the extra levels in the stratosphere.

*Note that NCEP has moved the LANDN variable to LAND. The WPS code handles this properly.

Additional details about the changes can be found here.