Dashboard
The Global Forecast System (GFS)
1) Overview
From 1980-2019, NCEP ran a global spectral model in the various production slots allocated for it.
Its evolution in the NCEP Production Suite can be tracked in the table below, and documentation on
the GFS spectral model can be found
here.
In 2017, the Finite Volume Cubed Sphere (FV3) dynamical core,
developed at NOAA’s Geophysical
Fluid Dynamics Laboratory, was selected for the new Unified Forecast System (UFS) atmospheric model
for both global and regional scales. At NCEP, the FV3 dynamical core implementation included
incorporating FV3 into NEMS, and developing advanced physics and data assimilation techniques
to match or exceed the skill of spectral model-based Global Forecast System (GFS). In addition,
NOAA/NWS is working with federal partners, universities, and the community to create a fully
accessible FV3-based community model, see the UFS Community page
and the UFS Weather Model page on GitHub.
The first implementation of the UFS Atmospheric model in NCEP occurred on June 12th 2019 with the
deployment of GFS Version 15 in the NCEP Production Suite (NPS). The major component of this implementation
was to replace the Global Spectral Model in the GFS with the FV3 dynamical core. The operational GFS version
15 runs the same physics as the previous GFS, except that the Zhao-Carr microphysics was replaced with the
more advanced GFDL microphysics scheme. More details on the 2019 implementation of the GFS version 15 can
be found in the NWS Service Change Notice
for this change, on EMC's GFS page on the NWS Vlab site, or
at the "Recent GFS Implementation details" link above. Comprehensive information on the official evaluation
of GFS v15 is available at the EMC GFS V15 Model Evaluation Group’s (MEG) web site.
On March 22th, 2021, NCEP implemented GFS version 16. In addition to the numerous model and data assimilation changes
that are described in the NWS Service Change Notice,
with this upgrade, NCEP is merging the operational standalone global deterministic WAVEWATCH III based wave model
Multi_1 into the GFS system. An updated version of the WAVEWATCH III model has been coupled to the GFS using a one-way
coupling scheme in which the atmospheric model provides forcing to the wave model using the NOAA Environmental Modeling System
(NEMS). Additional information can be found on the EMC Model Evaluation Group’s GFS v16 website, which includes numerous links
to presentations showing details on GFS v16 model/assimilation changes and performance evaluations.
The following table shows the evolution of NCEP global model since 1980, also see https://www.emc.ncep.noaa.gov/gmb/STATS/html/model_changes.html. See the JNWPU/NMC/NCEP Global/Hemispheric Model History Page for a list of all Global/Hemispheric Models from 1958-Present.
Year |
Model |
Horizontal Resolution/Vertical
Layers |
Forecast
length |
Note |
Documents |
1980 |
Spectral;
Eulerian |
R30L12 |
48h |
Rhomboidal Truncation |
|
1983 |
Spectral;
Eulerian |
R40L12 |
240h
@ 00Z |
MRF |
|
1985 |
Spectral;
Eulerian |
R40L18 |
240h
@ 00Z |
MRF |
|
1987 |
Spectral;
Eulerian |
T80L18 |
240h
@ 00Z |
MRF, triangular truncation |
|
1991 |
Spectral;
Eulerian |
T126L18 |
240h
@ 00Z |
MRF |
|
1993 |
Spectral;
Eulerian |
T126L28 |
240h
@ 00z |
MRF,
SAS convection |
|
2000 |
Spectral;
Eulerian |
T170L42
to 144h, T62L28 |
384h
@ 00Z, 84h @ 06/12/18z |
MRF/AVN,
Prognostic ozone; NASA
SW |
|
2002 |
Spectral;
Eulerian |
T170L42
to 144h, T62L28 to 384h |
384h
4x/day |
RRTM LW |
|
2002 |
Spectral;
Eulerian |
T254/64
to 84h, T170/42 to 180h, T126/28 to 384h |
384h
4x/day |
Now
called GFS |
|
2005 |
Spectral;
Eulerian |
T382L64
to 180h, T190L64 to 384h |
384h
4x/day |
2L OSU to 4L NOAH LSM |
|
2007 |
Spectral;
Eulerian |
T382L64
to 180h, T190L64 to 384h |
384h
4x/day |
Hybrid-sigma
vertical coordinate, GSI analysis |
|
2010 |
Spectral;
Eulerian |
T574L64
to 192h T190L64
to 384h |
384h
4x/day |
RRTM SW; TVD tracer transport |
|
2012 |
Spectral;
Eulerian |
T574L64
to 192h, T190L64
to 384h |
384h
4x/day |
Hybrid
variational ensemble (T254) DA |
|
2015 |
Spectral;
Semi-Lagrangian |
T1534L64
to 240h T574L64
to 384h |
384h
4x/day |
||
2016 |
Spectral;
Semi-Lagrangian |
T1534L64
to 240h T574L64
to 384h |
384h
4x/day |
4D
Hybrid Ensemble-Variational Data Assimilation; |
|
2017 |
Spectral;
Semi-Lagrangian |
T1534L64
to 240h T574L64
to 384h |
384h
4x/day |
NEMS ; NSST |
|
2019 |
FV3 |
13 km
/ 64 levels |
384h
4x/day |
Increase
resolution of ensemble DA from 35km to 25km; GFDL Microphysics |
|
2021 |
FV3 |
13 km
/ 127 levels |
384h
4x/day |
One-way
coupling to NCEP wave model |
2) GFS v15 Documentation
EMC Model Evaluation Group’s (MEG) GFSv15 web page
NCEP/EMC Change Control Board Presentation
GFSv15 NOAA/NWS Evaluation Summary
NCEP Office of the Director Science and Decisional Brief on GFSv15
3) GFS v16 Documentation
GFSv16 Service Change Notice (for science / output changes)
GFSv16 Service Change Notice (timing changes for downstream NCEP Production Suite systems)
NCEP/EMC Change Configuration Board Presentation
GFS Wave vs. Multi-1 Evaluation Summary
GFSv16 Field Evaluations (Waves/Days 1-10 Weather)
GFSv16 NWS SOO Team Evaluation Overview
GFSv16 EMC MEG Evaluation and Overview
NCEP Office of the Director Science and Decisional Briefing: Summary
NCEP Office of the Director Science and Decisional Briefing: Field Evaluations