GFSv16.1.1

RFC 8196 - On WCOSS, implement the GFS v16.1.1 upgrade to begin assimilating GPS radio occultation (GPS-RO) data from GeoOptics for all forecasts as long as the data are available. This upgrade also addresses several bugs from v16.0.0:

• 2021 tropical storm update
• Fixes the calculation of the layer height increment
• Includes RW-NH* boundary points in the wave component
• Fixes the East Pacific wave grid interpolation to include all American Samoa islands
• Unmasks the Gulf of California, Red Sea and Persian Gulf in 0p25 global interpolated wave output grids
• Fixes a bitmask issue in 0p25 deg blended WAFS icing and turbulence products below 500 hPa.

Implemented May 20 2021 at 12z.

SCN: https://www.weather.gov/media/notification/pdf2/scn21-52_gfsv16.1.1.pdf

GFSv16.0.9

GFS version 16.0 is the first major upgrade to Finite Volume Cubed Sphere (FV3) dynamical core based GFS which replaced the spectral dynamical core in June 2019. In this upgrade, the number of model vertical layers is increased from 64 to 127 and the model top is extended from the upper stratosphere (~55 km height) to the mesopause (~80 km height). With this upgrade, for the first time, the operational stand alone global deterministic WAVEWATCH III based wave model Multi_1 (wave_multi_1.v3.3) is merged into the GFS system. The WAVEWATCH III model is updated and coupled to the GFS using a one-way coupling scheme where the atmospheric model provides forcing to the wave model using the NOAA Environmental Modeling System (NEMS). Major changes have also been made in other components of the forecast system including model physics, data assimilation, system infrastructure, post-processing and product generation.

Merged final GFSv16 (v16.0.9) package into operations branch. GFSv16.0.7 system implemented March 22nd 2021 @ 12z. Follow-up updates/fixes resulting in v16.0.8 (~March 31st) and v16.0.9 (April 27th 12z) were implemented.

GFSv15.3.5

The GFS was updated in operations to v15.3.5. The versions of the gempak and bufr libraries were updated ahead of a January 1st 2021 bug.

(Note - v15.3.4 tag was skipped since updates in ops for that were to fix files that are external to GFS system (new 2021 CO2 files). The v15.3.4 system is otherwise identical to the v15.3.3 system tag.)