NOUS41 KWBC 302018

PNSWSH

 

Service Change Notice 16-23

National Weather Service Headquarters Washington DC

418 PM EDT Thu Jun 30 2016

 

To:         Subscribers:

            -NOAA Weather Wire Service

            -Emergency Managers Weather Information Network

            -NOAAPORT  

            -Other NWS Partners, Users and Employees

 

From:       Eli Jacks,

            Chief, Forecast Services Division

 

Subject:    Experimental Wind Speed Probabilities–Based Tropical

            Cyclone Danger Area Graphic to transition from

            experimental status to operational status effective

            August 1, 2016

 

Effective August 1, 2016, the NWS National Hurricane Center (NHC)

Tropical Analysis and Forecast Branch (TAFB) will provide, on an

operational basis, the event-driven Wind Speed Probabilities–

Based Tropical Cyclone Danger Area Graphic for both the Atlantic

and East Pacific basins.

 

TAFB has provided, on an experimental basis, a Tropical Cyclone

Danger Area Graphic when there is an active tropical cyclone. 

The graphic is generated based on the 34-kt wind speed

probabilities through 72 hours from the latest tropical cyclone

advisory using the 5 percent and 50 percent 34-kt wind speed

probability contours for both the Atlantic and East Pacific

basins.

 

The legacy Tropical Cyclone Danger Area graphic uses the

mariners' 1-2-3 rule to outline avoidance areas for active

tropical cyclones. Feedback from users indicated that the 1-2-3

methodology has led to over-warned large avoidance areas. TAFB

will terminate the legacy mariners 1-2-3 version after the Wind

Speed Probabilities–Based Tropical Cyclone Danger Area Graphic is

operational.

 

In the event there are no active tropical cyclones in either

basin, the graphic will be blank with the following wording:

 

THERE IS NO TROPICAL CYCLONE ACTIVITY IN THE ATLANTIC

 

Or

 

THERE IS NO TROPICAL CYCLONE ACTIVITY IN THE EAST PACIFIC

 

The tropical cyclone danger area graphics will be available four

times daily during hurricane season at 0400, 1000, 1600 and 2200

Universal Coordinated Time (UTC) on the National Hurricane Center

(NHC) website at:

 

      http://www.nhc.noaa.gov/marine/#graphical

 

A comprehensive description of the tropical cyclone danger area

graphic is posted at:

 

      http://www.nhc.noaa.gov/experimental/danger/

 

If you have comments or questions, please contact:

 

Hugh Cobb

Chief, Tropical Analysis and Forecast Branch

National Hurricane Center

E-mail:  Hugh.Cobb@noaa.gov

Phone:   305-229-4454

 

National Service Change Notices are online at:

 

      http://www.nws.noaa.gov/om/notif.htm

 

NNNN