July 8, 2019 - Fixed errors found in GFS precipitation field
Update: the errors found in the GFS precipitation fields have been fixed as of 12 UTC on July 8, 2019. All precipitation fields in the forecast GFS, GFSLR, and 0.25 degree GFS files are now 6 hour accumulated precipitation amounts.
We found bugs in the HYSPLIT-compatible GFS files related to precipitation. HYSPLIT should not be run with wet deposition until this is resolved and meteograms will not show all the precipitation that is actually predicted.
In the 0.25 degree GFS (hysplit.tCCz.gfs0p25f), the precipitation in the file is labeled TPPA (total accumulation) but it is really TPP6 (up to 6-h accumulation). READY meteorograms (and similary 2-d graphical plots of precipitation) give correct 3-h precipitation every 6 hours, but zero precipitation at other times, and what is given on the meteorogram as Total precipitation is incorrect because the zero values may be incorrect. This affects the archive files in ftp://ftp.arl.noaa.gov/archives/gfs0p25/. Archive files prior to this period are at ftp://ftp.arl.noaa.gov/archives/gfs0p25.v1/
In the 1 degree GFS (hysplit.tCCz.gfsf), the precipitation at forecast hour zero (+0) is incorrect.
In the GFS archive file (hysplit.tCCz.gfsa), because this is a concatenation of +0, +3-hour forecasts from successive cycles, every 00, 06, 12, 18 UTC precipitation is incorrect.
We expect to give NOAA NCEP revised code next week. We apologize for the inconvenience. Another announcement will be made here once the files have been corrected.