####018002188####
WTNT44 KNHC 130234

TCDAT4

 

Tropical Storm Sean Discussion Number   9

NWS National Hurricane Center Miami FL       AL192023

1100 PM AST Thu Oct 12 2023

 

Sean continues to be a sheared tropical cyclone.  The exposed 

low-level center is gradually becoming more displaced from the 

deepest convection in the northeast quadrant.  Surprisingly, 

satellite wind data that partially captured the center of the storm 

revealed winds of 38-39 kt.  Therefore, despite Sean's ragged 

appearance, the initial intensity is raised to 40 kt for this 

advisory.

 

The cyclone is accelerating west-northwestward at an estimated 

300/12 kt.  Sean is being steered by a weak ridge centered over the 

eastern tropical Atlantic.  This ridge is expected to build westward 

and keep Sean on a west-northwestward to northwestward track with a 

decrease in forward speed through the forecast period.  The 

guidance envelope is decently clustered, and the latest advisory 

lies close to the various consensus aids and just south of the 

previous track forecast.

 

Environmental conditions are generally not conducive for additional

strengthening.  Persistent moderate-to-strong deep-layer vertical

wind shear and an increasingly dry airmass should inhibit further

development of the storm.  The model guidance envelope shows Sean

gradually weakening for the next couple of days.  By the end of the

weekend, the storm is expected to lose its convective organization

and become a remnant low.  The latest NHC intensity prediction has

been slightly raised in the near-term forecast hours based on

Sean's initial intensity.  Dissipation is still anticipated within

4 days.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  13/0300Z 14.1N  39.5W   40 KT  45 MPH

 12H  13/1200Z 14.9N  40.8W   40 KT  45 MPH

 24H  14/0000Z 16.1N  42.3W   35 KT  40 MPH

 36H  14/1200Z 17.3N  43.6W   35 KT  40 MPH

 48H  15/0000Z 18.4N  44.7W   30 KT  35 MPH

 60H  15/1200Z 19.2N  45.6W   25 KT  30 MPH...POST-TROP/REMNT LOW

 72H  16/0000Z 20.1N  46.6W   25 KT  30 MPH...POST-TROP/REMNT LOW

 96H  17/0000Z...DISSIPATED

 

$$

Forecaster Bucci