NOUS41 KWBC 281520



Technical Implementation Notice 12-09

National Weather Service Headquarters Washington DC

1020 AM EST Tue FEB 28 2012


To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          -Other NWS Partners, Users and Employees


From:     Tim McClung

          Science Plans Branch Chief

          Office of Science and Technology


Subject:  Addition of Experimental 2.5-km GFS-based

          Gridded MOS Guidance for CONUS


Effective immediately, NWS is producing experimental Global Forecast System (GFS)-based gridded MOS guidance for the CONUS at 2.5-km resolution. These products are now available on the NWS FTP server in GRIB2 format. GRIB2 file names for each gridded MOS element are listed in Table 1 below.  On a future date to be announced, these products will be disseminated across the Satellite Broadcast Network (SBN) and NOAAPORT.


These gridded MOS products contain guidance on a 2.5 km Lambert Conformal grid covering the same expanse as the National Digital Forecast Database (NDFD) CONUS grid. Grids are being generated from the 0000 and 1200 Universal Coordinated Time (UTC) model runs at projections of 1 to 7 days in advance. Guidance is available for the following elements:


  Daytime Maximum and Nighttime Minimum Temperature

  2-Meter Temperature

  2-Meter Dewpoint Temperature

  Relative Humidity

  Wind Direction

  Wind Speed

  Wind Gusts

  Probability of Precipitation /6-h and 12-h/

  Probability of a Thunderstorm /3-, 6-, and 12-h/

  Quantitative Precipitation Amount /6-h and 12-h/

  Total Sky Cover

  24-h Snowfall Amount 


On a date to be announced, NWS will replace the 2.5-km gridded MOS probability of precipitation (PoP) and quantitative precipitation forecasts (QPF) with an enhanced-resolution PoP and QPF product (HRMOS QPF). The improved QPF forecasts are developed from archived stage IV national mosaic precipitation data and incorporate high resolution topographic and climatological interactive predictors.  The following link provides details about the enhanced-resolution PoP and QPF:


A Web page providing more information regarding grid specifications, GRIB2 encoding and elements for which guidance is available is referenced below.


These GRIB2 products are now available in the experimental area of the National Digital Guidance Database (NDGD) on the NWS ftp server.  Forecast guidance for days 1 through 3 is available at:


Forecast guidance for days 4 through 7 are available at:


Table 1: GRIB2 file names for each experimental 2.5-km GFS-based Gridded MOS element


     FILE NAME       ELEMENT      Total Sky Cover

     ds.wdir.bin     Wind Direction

     ds.wspd.bin     Wind Speed

     ds.pop12.bin    12-Hour Probability of


     ds.temp.bin     2-Meter Temperature       2-Meter Dew Point Temperature

     ds.maxt.bin     Daytime Maximum Temperature     Nighttime Minimum Temperature

     ds.qpf06.bin    6-h Quantitative Precipitation


     ds.pts06.bin    6-h Probability of a Thunderstorm

     ds.rhm.bin      Relative Humidity

     ds.snw24.bin    24-h Snowfall Amount

     ds.pop06.bin    6-Hour Probability of


     ds.gpf12.bin    12-h Quantitative Precipitation


     ds.wgust.bin    Wind Gusts

     ds.pts12.bin    12-h Probability of a


     ds.pts03.bin    3-h Probability of a Thunderstorm


The experimental 2.5 km products are an addition to the gridded MOS suite, not a replacement for the current 5 km gridded MOS guidance. Customers who use the 5 km guidance over the CONUS can continue to use these products without disruption until all customers and systems are able to use the higher resolution guidance.


A Web page outlining the gridded MOS guidance and the FTP server structure can be found at:


For questions regarding the experimental 2.5 km gridded MOS guidance for the CONUS please contact:


  Kathryn Gilbert

  MDL/Silver Spring, Maryland

  301-713-0023, Ext. 130


Links to the gridded MOS products and descriptions are at:


NWS national TINs are online at: