NOUS41 KWBC 031515

PNSWSH



Public Information Statement 26-08

National Weather Service Headquarters Silver Spring MD

1015 AM EST Tue Feb 3 2026



To:	 Subscribers:

	 -NOAA Weather Wire Service

	 -Emergency Managers Weather Information Network

	 -NOAAPort

	 Other NWS Partners, Users and Employees



From:	 Debra Blondin

	 Acting Director

	 NCEP/Aviation Weather Center



Subject: Soliciting Comments on Experimental Graphical

Turbulence Guidance (GTG) Nowcast (GTGN) product through March

5, 2026



The National Weather Service (NWS) is soliciting user comments

on the Aviation Weather Center’s (AWC) experimental GTGN product

through March 5, 2026.	This product is designed to provide a

near real-time analysis of in-flight turbulence every 15

minutes, significantly enhancing support for the aviation

community.  GTGN uses a short-term (1 or 2-hour) forecast from

the GTG as the basis for the nowcast.  Recent observations of

turbulence are then used to update the GTG forecast and create a

blended analysis.  Observational datasets currently used by GTGN

include aircraft observations from pilot reports (PIREPs),

automated in situ energy (eddy) dissipation rate (EDR) reports,

EDR estimated from ground-based radar observations via the

Nexrad Turbulence Detection Algorithm (NTDA), estimated EDR from

lightning data and METAR data.	The output of GTGN is energy

dissipation rate to the one third power, or EDR. EDR is an

atmospheric, aircraft independent metric of turbulence. The GTG

forecast is based on NOAA’s 3-km High-Resolution Rapid Refresh

(HRRR) model over the CONUS, and thus its domain serves as the

horizontal domain for GTGN.  The vertical resolution of the

nowcast starts at the surface (100 feet) and is output at every

1,000 feet up to 50,000 feet.



The GTGN display at the below experimental webpage will be

upscaled to a 13-km horizontal resolution from the native 3-km

to align with the AWC website framework.  Additionally, levels

3,000 feet up to 42,000 feet in 3,000 foot intervals will be

displayed, along with EDR maximums above and below 18,000 feet.

These maximums are post-processed using all vertical levels

above and below 18,000 feet.



The experimental GTG Nowcast product display is available at the

following location:



https://testbed.aviationweather.gov/gtgn/



Input on the GTGN is being sought from user via the feedback

form below:



Google Form: https://forms.gle/4Yri2PyJxB5hU59x8



Note that data on the testbed webpage is subject to outages when

the development Weather and Climate Operational Supercomputing

System (WCOSS) machine is unavailable for maintenance or if

input data is otherwise unavailable.  Please submit comments,

questions, or requests pertaining to the experimental GTGN to:



Robert Hepper

NCEP/Aviation Weather Center

Email: robert.hepper@noaa.gov



National Public Information Statements are online at:



https://www.weather.gov/notification/