Tropical Storm Sean Forecast Discussion Number 14

By | October 14, 2023

WTNT44 KNHC 140836

Tropical Storm Sean Discussion Number  14
NWS National Hurricane Center Miami FL       AL192023
500 AM AST Sat Oct 14 2023

Sean has been producing bursts of deep convection overnight that 
have obscured the center of the cyclone.  The bursts do not appear 
to have much organization, and the latest subjective and objective 
satellite intensity estimates range from about 25 to 40 kt. The 
initial intensity for this advisory is kept at 35 kt, which is in 
agreement with the latest TAFB Dvorak CI number of T2.5 (35 kt). 
However, this could be generous. 

Sean is moving west-northwestward or 300 degrees at about 7 kt. 
The cyclone should turn northwestward today around the southwestern 
periphery of a narrow ridge over the eastern-central Atlantic.  A 
turn back toward the west-northwest is anticipated on Sunday when 
Sean weakens and becomes more vertically shallow.  There is a fair 
amount of spread in the track guidance that is related to how 
quickly Sean weakens.  The ECMWF which is the weaker of the 
dynamical models takes the cyclone on a more southerly track.  The 
NHC forecast is a little south of the previous advisory, especially 
at 48 and 60 hours, and lies near the middle of the guidance 

Sean is forecast to encounter an increasingly dry mid-level 
environment during the next couple of days, which should cause 
gradual weakening during that time.  The global model guidance 
indicates that Sean will struggle to produce deep convection by 
later today and Sunday, and it seems likely that the system will 
degenerate into a remnant low by 36 hours, if not sooner.  The 
circulation is expected to open up into a trough in 60 to 72 hours, 
and dissipation is indicated in the official forecast by day 3.  


INIT  14/0900Z 15.4N  43.4W   35 KT  40 MPH
 12H  14/1800Z 16.1N  44.2W   30 KT  35 MPH
 24H  15/0600Z 16.9N  45.4W   30 KT  35 MPH
 36H  15/1800Z 17.5N  47.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  16/0600Z 17.9N  48.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  16/1800Z 18.1N  50.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 72H  17/0600Z...DISSIPATED

Forecaster Brown

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