GFS - Global Forecast System
|Provider:||National Centers for Environmental Prediction, NOAA (USA)|
|Update frequency:||every 6 hours|
|Resolution:||0.25°, 15.0nm, 27.8km|
|Model duration:||61 forecasts starting at 0 hr, ending at 16 days|
|Parameters:||pressure, wind, wind gust, rain, cloud, temperature, humidity, dew point, convection, wind wave, swell, swell/wave combined, ice, vorticity, vertical velocity, simulated radar, precipitable water, visibility, 0C isotherm, 250 mb, 500 mb, 850 mb|
|GRIB model date:||Thu Sep 21 00:00:00 2023 UTC|
|Download date:||Thu Sep 21 05:49:40 2023 UTC|
|Download delay:||5hr 49min|
Note: the Download delay is the amount of time required for the GRIB model to compute its forecast and then for the LuckGrib cluster to download the data and make it available. The LuckGrib delay is generally less than 10 minutes, the remainder of the delay is the model compute time.
GFS is the most commonly used weather forecast model and is a good choice for those who are new to using GRIB forecast data. GFS has global coverage and the LuckGrib server provides access to up to 16 days of forecast data.
The following description has been taken directly from the official documentation
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…
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.
Description of Wave parameters (WW3.)
(Updated on March 22nd, 2021.)
As of the GFS update to v16 in late March 2021, GFS now includes what used to be the WW3 ocean data.
While this model is global, many seas and all lakes are not covered. For example, the Great Lakes are not covered by this model. If you are interested in the North American Great Lakes, please see the WW3 Great Lakes model.
This model contains parameters that describe the primary swell, the secondary swell, wind waves and the primary wave. Wind waves are self explanatory - they are the waves caused by the wind. Often on the ocean, there is more than one swell wave present, for example when an area is affected by more than one strong weather system. The largest swell wave that is present is called the primary swell. The second largest swell wave present is the secondary swell.
An interesting parameter is the primary wave, which is either the primary swell or the wind wave, whichever is greater for each point in the model. (This description may be simplified, but I believe captures the essence of what the primary wave represents.)
June 12, 2019 note on GFS update.
GFS is normally updated each year, year after year, steadily improving. This years update is larger than normal. For a number of years the folks at NOAA have been working on a big update to GFS - this was called the FV3-GFS.
This next generation GFS, now called GFS v15.1, has been available through LuckGrib for over a year as a research model. Many people had been downloading the new version of GFS and comparing its forecasts to the production version of GFS, at that time, GFS v14.
As of the 12Z cycle of GFS on June 12th, all downloads of GFS are of the newly updated model. If you have built GRIB requests for the next generation GFS, those requests will continue to work, however they now return the production GFS data.
If you are interested, the official service change notice detailing this update is available.
Contratulations to the entire NOAA team who worked on this update!