Frequently Asked Questions & Reported Issues about FY17 GFS

Below are frequently asked questions and known issues with the operational Q3FY17 GFS system. To see information on FAQs and known issues with the parallel/developmental version of the system on supported HPCs please see the following page: https://vlab.noaa.gov/group/gfs/faq-known-issues

Date
Issue/Question
Resolution/Answer
9/2017 Locating near surface sea temperature (NSST) from GFS upgrade NSST data from ops GFS can be found on WCOSS here:
deterministic: $COMROOThps/{gfs,gdas}.$PDY/{gfs, gdas}.t${cyc}z.nst*.nemsio
EnKF: $COMROOThps/enkf.$PDY/$cyc/gdas.t${cyc}z.nst*nemsio
Users on WCOSS can echo $COMROOThps when the prod_envir module is loaded.
8/2017 Missing pgrb2_0p50 tarballs in previous production runhistory. User can recreate 0.5 degree from 0.25 degree files. Current production run history contain pgrb2_0p25.tar, pgrb2_0p50.tar, and pgrb2_1p00.tar files.
8/2017 Production runhistory tarballs for gfs sigma, surface, and sfluxgrb files contain full directory path. After extract the tar ball, the target files in question will located under .../gpfs/hps/nco/ops/com/gfs/prod/gfs.YYYYMMDD
8/2017 Pressure of cloud level types too large in pgrb2 files

We now use a much larger value of e+20 to represent grid points that do not have valid
values (i.e. the grid points that do not have clouds). Please use the latest wgrib2 decoder: ftp://ftp.cpc.ncep.noaa.gov/wd51we/wgrib2/
8/2017 Value range of soil moisture analyses changed from 0-1 to 10^11 Please use the latest wgrib2 decoder: ftp://ftp.cpc.ncep.noaa.gov/wd51we/wgrib2/
8/2017 GFS AWIPS 20 km grid potential vorticity (PV) surface level issue

RFC #3622 – GFS v14.0.2 - This update fixed a GFS AWIPS 20 km grid potential vorticity (PV) surface level issue for CONUS, Alaska, Puerto Rico, and Pacific Regions. Implemented on August 10 at 1800Z.
8/2017 GFS217(Alaska domain) have wind significant deviation on all levels. Solution found, fix submitted to NCO.
7/2017 NESDIS found RH value large than 100% from GFS pgb data files at 1.0 degree. NESDIS has workaround so fix will be implemented in next GFS upgrade.
5/2017 Bit maps are missing in GFS and GDAS pgb files EMC found out that the root cause is bit maps were unintentionally removed during pgb file creation. Russ indicated that wgrib2 option "-set_bitmap 1" might fix the issue.