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NOUS41 KWBC 271147 CCA

Technical Implementation Notice 16-38 Corrected
National Weather Service Headquarters Washington DC
747 AM EDT Thu Oct 27 2016

To:  Subscribers:
  -NOAA Weather Wire Service
  -Emergency Managers Weather Information Network
  Other NWS Partners, Users and Employees

From:  Eli Jacks
  Chief, Forecast Services Division

Subject:  Corrected: Addition of grids for the 0.25 inch (~6 mm)
  threshold of Experimental Day 4-7 Winter Weather
  Outlook as an experimental element in the National
  Digital Forecast Database (NDFD) for the CONUS
  effective October 11, 2016

Corrected TIN number to 16-38

Effective October 11, 2016, at 1930 Coordinated Universal Time
(UTC), NWS will add grids for the 0.25 inch (~6 mm) threshold of
the Experimental Day 4-7 Winter Weather Outlook to the National
Digital Forecast Database (NDFD) as an experimental element for
the Continental United States.

The Experimental Day 4-7 Winter Weather Outlook, produced by the
NWS National Centers for Environmental Prediction (NCEP) Weather
Prediction Center (WPC), is a forecast depicting the probability
of winter precipitation (snow/sleet) exceeding 0.25 inches (~6
mm) water equivalent over a 24-hour period (Valid Time 12z-12z).

The product is comprised of 4 separate grids containing the
forecast for Days 4, 5, 6 and 7. The product is updated daily at
approximately 0900 UTC and 1930 UTC.

More details on the Experimental Day 4-7 Winter Weather Outlook
product, as well as its technical description and scientific
basis, are available in the Product Description Document:

These experimental grids will be available from NDFD in the
following standard methods:

-Gridded Binary version 2 (GRIB2) files via Hypertext Transfer
Protocol (HTTP) and File Transfer Protocol (FTP)
-Extensible Markup Language (XML) via Simple Object Access
Protocol (SOAP)
-Graphics via Web browser

Users who pull NDFD elements in GRIB2 format, either via the
Internet may need to update their procedures and scripts to
access this new element.

The new file will be available for download at the following
links effective October 11, 2016:

GRIB2 files:

Graphics and XML services for the experimental grids will become
available within 30 days of the experimental release of the
GRIB2 file into the NDFD.

NDFD online graphics:

XML SOAP service:

Information on accessing and using NDFD elements is online at:

Comments and feedback on these experimental elements are welcome
through March 31, 2017 at:

GRIB2 users:

Users of XML SOAP service:

NDFD online graphics:

For general questions regarding NDFD data, please email:

For technical questions regarding NDFD data please contact:

 David Ruth
 NWS/STI/Digital Forecast Services Branch
 National Weather Service Headquarters
 Silver Spring, Maryland 20910

For questions regarding this notice, please contact:

 James Nelson
 NWS/WPC/Development and Training Branch
 National Centers for Environmental Prediction
 College Park, MD 20740

Technical Implementation Notices (TIN) specifically related to
the NDFD are online at:

National TINs are online at: is the U.S. government's official web portal to all federal, state and local government web resources and services.