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Global Forecast System (GFS)

An animation of GFS simulated total atmospheric ozone concentration

An animated image of GFS simulated total atmospheric ozone concentration, forecast from 00 UTC on July 12, 2012, to July 16, 2012, at 00 UTC—a four day forecast—in three hourly intervals. The lowest concentrations of ozone on the planet reside over the Antarctic during this period. This image was produced with the Grid Analysis and Display System (GrADS) and ImageMagick.

The Global Forecast System (GFS) is a weather forecast model produced by the National Centers for Environmental Prediction (NCEP). Dozens of atmospheric and land-soil variables are available through this dataset, from temperatures, winds, and precipitation to soil moisture and atmospheric ozone concentration. The entire globe is covered by the GFS at a base horizontal resolution of 18 miles (28 kilometers) between grid points, which is used by the operational forecasters who predict weather out to 16 days in the future. Horizontal resolution drops to 44 miles (70 kilometers) between grid point for forecasts between one week and two weeks.

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The GFS model is a coupled model, composed of four separate models (an atmosphere model, an ocean model, a land/soil model, and a sea ice model), which work together to provide an accurate picture of weather conditions. Changes are regularly made to the GFS model to improve its performance and forecast accuracy. It is a constantly evolving and improving weather model. Gridded data are available for download through the NOAA National Operational Model Archive and Distribution System (NOMADS). Forecast products and more information on GFS are available at the GFS home page.

Prior to January 2003, the GFS was known as the GFS Aviation (AVN) model and the GFS Medium Range Forecast (MRF) model. GFS-AVN and MRF products are a collection from NCEP's NOAAPort. Grids, domains, run frequencies, and output frequencies have changed over the years.

Product Types

GFS Analysis

Model Grid/Scale Period of Record Model Cycle Output Timestep Data Access Links
GFS-ANL 004 (0.5º) - Domain 01Jan2007–Present 4/day: 00, 06, 12, 18UTC +00, (+03, +06 precipitation fields) Plot|FTP4u FTP HTTP GDS TDS HAS
GFS-ANL 003 (1º) - Domain 02Mar2004–Present 4/day: 00, 06, 12, 18UTC +00, (+03, +06 precipitation fields) Plot|FTP4u FTP HTTP GDS TDS HAS

GFS Forecasts

Model Grid/Scale Period of Record Model Cycle Output Timestep Data Access Links
GFS 004 (0.5º) - Domain 10Oct2006–Present (approx. two years to present online) 4/day: 00, 06, 12, 18UTC 3-hourly, +000 to +192 hours Plot|FTP4u FTP HTTP TDS HAS
GFS 003 (1º) - Domain 15Feb2005–Present (approx. 6mo to present online) 4/day: 00, 06, 12, 18UTC 3-hourly, +000 to +240 hours; 12-hourly, +252 to +384 Plot|FTP4u FTP HTTP GDS TDS HAS
GFS-AVN 003 (1º) - Domain 02Mar2004–15Feb2005 4/day: 00, 06, 12, 18UTC 3-hourly, +000 to +240 hours Plot|FTP4u HAS

Legacy NCEP NOAAPort GFS-AVN and GFS-MRF Analysis and Forecasts

Model Grid/Scale Period of Record Model Cycle Output Timestep Data Access Links
GFS-AVN 211 (81km) - Domain 01Jan2003–30Nov2004 4/day: 00, 06, 12, 18UTC 6-hourly, +000 to +180 hours; 12-hourly +192 to +240 hours Plot|FTP4u FTP HTTP
GFS-AVN 213 (95km) - Domain 01Jan2003–30Nov2004 4/day: 00, 06, 12, 18UTC 6-hourly, +000 to +120 hours Plot|FTP4u FTP HTTP
GFS-AVN 203 (190km) - Domain 01Feb2003–30Nov2004 4/day: 00, 06, 12, 18UTC 6-hourly, +000 to +120 hours Plot|FTP4u FTP HTTP
GFS-AVN 202 (190km) - Domain 01Jan2003–30Nov2004 4/day: 00, 06, 12, 18UTC 6-hourly, +000 to +120 hours Plot|FTP4u FTP HTTP
GFS-AVN 201 (381km) - Domain 01Jan2003–30Nov2004 4/day: 00, 06, 12, 18UTC 6-hourly, +000 to +120 hours Plot|FTP4u FTP HTTP
GFS-MRF 205 (190km) - Domain 01Feb2003–30Nov2004 1/day: 00UTC 12-hourly, +000 to +240 hours Plot|FTP4u FTP HTTP
GFS-MRF 203 (190km) - Domain 01Feb2003–30Nov2004 1/day: 00UTC 12-hourly, +000 to +240 hours Plot|FTP4u FTP HTTP
GFS-MRF 202 (190km) - Domain 01Jan2003–30Nov2004 1/day: 00UTC 12-hourly, +000 to +240 hours Plot|FTP4u FTP HTTP
GFS-MRF 201 (381km) - Domain 01Jan2003–30Nov2004 1/day: 00UTC 12-hourly, +000 to +240 hours Plot|FTP4u FTP HTTP

Data Usage Notes

April 2003: GFS-AVN Grids Mislabeled

Messages for GFS-AVN will contain multiple records and one of the records will contain data from a different grid. In the sample below, the message contains two records. The first record contains data for grid 202; this is consistent with the WMO header. The octet 3 is "I" which indicates grid 202. However, record 2 contains data for grid 201 as indicated by octet 7 (value hex C9) in the PDS header. We have also found files with grid 203 data that also contain data from grid 201.

wgrib -V -o /dev/null -PDS -GDS YHIN25_KWBC_20030326_0000
rec 1:21:date 2003032600 HGT kpds5=7 kpds6=100 kpds7=250 levels=(0,250) grid=202 250 mb 108hr fcst:
HGT=Geopotential height [gpm]
timerange 10 P1 0 P2 108 TimeU 1 nx 65 ny 43 GDS grid 5 num_in_ave 0 missing 0
center 7 subcenter 0 process 96 Table 2
polar stereo: Lat1 7.838000 Long1 -141.028000 Orient -105.000000
north pole (65 x 43) Dx 190500 Dy 190500 scan 64
PDS(1..28)=
1: 00 00 1c 02 07 60 ca 80 07 64 00 fa 03 03 1a 00 00 01 00 6c
21: 0a 00 00 00 15 00 00 01
GDS(1..32)=
1: 00 00 20 00 ff 05 00 41 00 2b 00 1e 9e 82 26 e4 08 81 9a 28
21: 02 e8 24 02 e8 24 00 40 00 00 00 00
min/max data 9469.1 10960.4 num bits 14 BDS_Ref 94691 DecScale 1 BinScale 0
rec 2:5018:date 2003032600 HGT kpds5=7 kpds6=100 kpds7=250 levels=(0,250) grid=201 250 mb 108hr fcst:
HGT=Geopotential height [gpm]
timerange 10 P1 0 P2 108 TimeU 1 nx 65 ny 65 GDS grid 5 num_in_ave 0 missing 0
center 7 subcenter 0 process 96 Table 2
polar stereo: Lat1 -20.826000 Long1 -150.000000 Orient -105.000000
north pole (65 x 65) Dx 381000 Dy 381000 scan 64
PDS(1..28)=
1: 00 00 1c 02 07 60 c9 80 07 64 00 fa 03 03 1a 00 00 01 00 6c
21: 0a 00 00 00 15 00 00 01
GDS(1..32)=
1: 00 00 20 00 ff 05 00 41 00 41 80 51 5a 82 49 f0 08 81 9a 28
21: 05 d0 48 05 d0 48 00 40 00 00 00 00
min/max data 9292.3 11006 num bits 15 BDS_Ref 92923 DecScale 1 BinScale 0

Publication References

None

Miscellaneous Documentation

None

Links

GrADS PDEF files for the NOAAPort grids can be downloaded from our site. These files are needed for using locally downloaded copies of certain datasets in GrADS.

NCEP GFS Home Rage

WMO Headers for NCEP AWIPS GFS Products made available to NOAAPORT