NOUS41 KWBC 141520



Service Change Notice 17-31

National Weather Service Headquarters Silver Spring, MD

1120 AM EDT Tue Mar 14 2017


To:       Subscribers:

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network


           Other NWS partners and employees


From:     William Bauman

          Chief, Aviation and Space Weather Services Branch


Subject:  Operational Implementation of Aviation Weather

          Center Experimental Graphical Forecasts for

          Aviation Effective April 13, 2017


Effective April 13, 2017, the Experimental Graphical

Forecasts for Aviation (GFA) produced by the NWS Aviation

Weather Center (AWC) will transition to operational status.


The experimental GFA were created in response to a formal

request by the Federal Aviation Administration (FAA) to

discontinue production of the textual Area Forecasts (FA).

Requirements for the underlying meteorological information

in the FA have not changed. The FAA recognizes that, given

modern advances within NWS, the legacy text FA is no longer

the best source of en route flight planning weather



The FAA, pursuant to Title 49 United States Code, Section

44720, established requirements for this weather

information and service which is necessary for the safe and

efficient conduct of operations in the National Airspace

System (NAS).  The new graphical forecasts are designed to

provide meteorological information equivalent to the

textual FA. The graphical product includes observations and

forecasts valid for the continental United States that

provide data critical for aviation safety and are overlaid

on high-resolution base-maps. FAs for Hawaii, Alaska, the

Caribbean, and Gulf of Mexico will not be affected at this



Observational data in the GFA are time-synchronized and

available by the hour for the current time and the previous

6 hours. Hourly model data are available for up to 15 hours

in the future. Wind, icing and turbulence forecasts are

available in 3000 ft. increments from the surface up to

Flight Level (FL) 180 or 18,000 ft. Mean Sea Level (MSL),

and in 6,000 ft. increments from FL180 to FL480 or 48,000

ft. MSL. Turbulence forecasts are also broken into LO

(below FL 180) and HI (FL180 and above) graphics.  Maximum

icing and maximum wind velocity graphics (regardless of

altitude) are also available.


Data including Observations/Warnings, Thunderstorms,

Clouds, Flight Category (Ceiling and Visibility),

Precipitation, Icing, Turbulence, and Winds are available

in the GFA.  These data are combined into categories that

the user can select from the top level menu. Details of

each category can be found in the Product Description

Document (PDD):


The GFA can be found at:


FAs will continue to be produced until formal notification

is provided by NWS in advance of discontinuation.


If you have any questions regarding the GFA, please



Debra Blondin

Domestic Operations Branch Chief

Aviation Weather Center

Kansas City, MO 64153



National Service Change Notices are online at: