NOUS41 KWBC 122050



Technical Implementation Notice 12-12

National Weather Service Headquarters Washington DC

350 PM EST Mon Mar 12 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:  Replacement of experimental 2.5-km Gridded MOS PoP/QPF with HRMOS PoP/QPF


On Tuesday, March 13, 2012, beginning with the 1200 Coordinated Universal Time (UTC) run, the experimental 2.5-km Global Forecast System (GFS)-based gridded MOS probability of precipitation (PoP) and quantitative precipitation forecasts (QPF) will be replaced by an enhanced-resolution PoP and QPF product (HRMOS QPF). 


See the PNS and TIN below:


Soliciting Comments on Proposed Enhancements to the Global Forecast System (GFS)-Based Gridded MOS Product Through November 30, 2011


TIN 12-09


Addition of Experimental 2.5-km GFS-based Gridded MOS Guidance for CONUS


These products will be available on the NWS FTP server in GRIB2 format. GRIB2 file names for the PoP and QPF guidance are listed in Table 1 below. On a date to be announced, these products will be disseminated across the Satellite Broadcast Network (SBN) and NOAAPORT.


The experimental 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 generated from the 0000 and 1200 UTC model runs at projections of 1 to 7 days in advance. The improved HRMOS PoP/QPF forecasts are based on gridded Stage IV precipitation data together with GFS model output, and incorporate high resolution topographic and precipitation climatology predictors. The following link provides additional details about the enhanced-resolution HRMOS PoP and QPF:


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 are available here:


Forecast guidance for days 4 through 7 are available here:


Table 1: GRIB2 file names for each experimental 2.5-km GFS-based PoP/QPF element




     ds.pop12.bin    12-h Probability of


     ds.gpf12.bin    12-h Quantitative Precipitation


     ds.pop06.bin    6-h Probability of


     ds.qpf06.bin    6-h Quantitative Precipitation



The experimental 2.5-km PoP/QPF products are an addition to the gridded MOS suite, not a replacement for the operational 5-km PoP/QPF 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 is online at:


For questions regarding the experimental 2.5-km gridded MOS POP/QPF guidance for the CONUS please contact:


  Jess Charba

  MDL/Silver Spring, Maryland

  301-713-1773, Ext. 179


  Fred Samplatsky

  MDL/Silver Spring, Maryland

  301-713-0224, Ext. 105


Links to the gridded MOS products and descriptions are online at:


NWS national TINs are online at: