NOUS41 KWBC 011823
Technical Implementation Notice 14-14
National Weather Service Headquarters Washington DC
225 PM EDT Tue Apr 1 2014
To:       Subscribers:
          - Family of Services
          - NOAA Weather Wire Service
          - Emergency Managers Weather Information Network
          - NOAAPORT
          Other NWS partners and NWS employees
From:     Eli Jacks 
          Chief, Fire and Public Weather Services Branch
Subject:  Combining fine resolution files in the experimental
          National Digital Forecast Database (NDFD) Effective 
          May 6, 2014
Effective Tuesday, May 6, 2014, at 1400 Coordinated Universal 
Time (UTC), the NWS will change the structure of the experimental 
NDFD, by combining individual day 1, day 2 and day 3 forecast 
files into a single day 1 through day 3 forecast file for each 
NDFD element. The new structure is the same as currently used 
in the operational NDFD.
This change will affect experimental files containing data for 
the entire CONUS, but will not affect Alaska, Hawaii, Guam, 
Puerto Rico and the Virgin Islands, or the pre-defined 16 CONUS 
subsectors, which already employ the combined file structure.
This implementation will affect CONUS forecast files available   
experimentally from NDFD in the following standard method:
- GRIdded Binary version 2 (GRIB2) files via Hypertext Transfer 
Protocol (HTTP)
- File Transfer Protocol (FTP).
Users who pull NDFD elements in GRIB2 format, either via the 
Internet or via the Family of Services server access service, 
may need to update their procedures and scripts to access 
these new elements.
To access experimental fine resolution grids, go to:
This change is being made to prepare for the transition to 
operational status of the finer resolution experimental NDFD.
If May 6, 2014, is a critical weather day, this implementation 
may be postponed. Users will be notified of that decision via another 
Technical Implementation Notice as far in advance as possible.
For general questions regarding NDFD data, please email:
For technical questions regarding NDFD data, please contact:
  David Ruth
  Chief, Mesoscale Prediction Branch
  NOAA/NWS Office of Science and Technology
  Silver Spring, Maryland 20910
For questions regarding this notice, please contact:
  Andy Horvitz
  National Weather Service
  Office of Climate Water and Weather Services
  Silver Spring, Maryland 20910
Technical Implementation Notices related to NDFD are online at:
All National Technical Implementation Notices are online at: