Attention users: Dissemination of all Gridded Model Output Statistics (GMOS) products is planned to be terminated on or about Tuesday, November 5, 2019, after the 1200 UTC model cycle time. More information can be found at Service Change Notification 19-28

Gridded MOS is an expansion of the Model Output Statistics technique used to improve numerical model forecasts by relating model outputs to observations via statistical methods. In Gridded MOS, MOS output calculated for meteorological ground station locations (see: GFS MOS,NAM MOS) are applied to a grid, such as that used by the National Digital Forecast Database. In the case of MDL, this application is done using a Bergthorssen-Doos-Cressman analysis technique, modified by Glahn. (See the Training References below for papers and presentations which discuss the development of GMOS in more detail.) 

For more in-depth discussion of MOS, the following are good places to start:

GMOS Products

Product Format Information and Documentation

Element and Projection Documentation

• Available Elements and Projections (PDF) - Updated 11/9/10

GMOS WMO Headers

• WMO Communication Headers for 5-km CONUS GMOS (PDF)
• WMO Communication Headers for 2.5-km CONUS GMOS (PDF) - Updated 12/19/2013
• WMO Communication Headers for 3-km Alaska GMOS (PDF) - Updated 12/19/2013

GRIB Encoding Information

• GRIB2 encoding of gridded MOS
• Description of gridded MOS GRIB2 ftp file structure (PDF) - Updated 11/13/12

Additional Training References

Additional Presentations 

• AMS Short Course - The Role of Model Output Statistics (MOS) in Downscaling of NWP Model Output [PDF]- Glahn 2006 (PowerPoint Presentation)
• Gridded MOS - Techniques, Status, and Plans [PDF] - Dallavalle and Glahn 2006 (PowerPoint Presentation)
• Gridded MOS Presentation for Western Region SOOs [PDF](PowerPoint Presentation)

Additional Papers

• Toward A Gridded MOS System [PDF]- Dallavalle and Glahn, 2005
• Using Geographical Information Systems to Develop Gridded Model Output Statistics [PDF]- Sheets et al., 2005
• Gridded MOS - Techniques, Status, and Plans [PDF]- Glahn and Dallavalle 2006
• MDL Office Note 06-01 - Performance of Three Forecast Systems at Selected MOS and Non-MOS Stations [PDF] -Schenk 2006
• Gridded model output statistics: Improving and expanding [PDF]- Gilbert et al. 2009

Operational (and Transitional) Products

Operational products are fully supported by NWS and are produced on a regular schedule by NCEP Central Operations.

GFS GMOS

Operational GMOS Suite

Predominant Weather

Experimental Products

Experimental products are still in development. They are produced and supported by the developers. These products may not be produced on a regular schedule. Comments and Suggestions are always welcome.