Technical Implementation Notice 10-62

National Weather Service Headquarters Washington DC

321 PM EST Wed Dec 15 2010


To:         Subscribers:

               -Family of Services

               -NOAA Weather Wire Service

               -Emergency Managers Weather Information Network


               Other NWS Partners, Users and Employees


From:       Timothy McClung

               Chief, Science Plans Branch

               Office of Science and Technology


Subject:  Change to GRIB encoding of WAFS products:

               Effective March 1, 2011


Effective Tuesday, March 1, 2011, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will modify the GRIB encoding of the GRIB2 World Area Forecast System (WAFS) products generated from the Global Forecast System (GFS). 


In the GRIB2 products, Section 1, Identification Section in the GRIB message, Octet 10, which indicates the WMO GRIB Master Table used to encode the data, will be changed from 2 to 6.  This change indicates that the products will be encoded and should be decoded using Master Table version number 6.  This change will occur only in the WAFS products, which are disseminated through the International Satellite Communications System (ISCS), and the World Area Forecast System Internet File System (WIFS).  This change will not affect any other NCEP GRIB2 products, GRIB1 products, or any products on NOAAPORT.


More information about how NCEP encodes products in GRIB2, including the WMO GRIB Master Tables, is available at:


For questions regarding these changes, please contact:


Bradley Mabe

NCEP/Central Operations

Camp Springs , Maryland

301-763-8000 x 7715


Rebecca Cosgrove

NCEP/Central Operations

Camp Springs , Maryland

301-763-8000 x 7198


NWS National Technical Implementation Notices are online at: