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Tropical Depression Sean Discussion Number  15
NWS National Hurricane Center Miami FL       AL192023
1100 AM AST Sat Oct 14 2023
 
Sean continues to have a lackluster satellite appearance, with  
intermittent burst of convection near the center this morning. 
Earlier noted convective bursts were fairly short lived, and didn't 
have much organization. Latest subjective and objective satellite 
intensity estimates range from 25 to 35 kt. With final-T numbers 
from SAB and TAFB both T1.5, with CI numbers of T1.5/T2.5, 
respectively. Given a blend of these values and the current 
satellite imagery, the initial intensity for this advisory is 
lowered to 30 kt. 
 
Sean is moving northwestward or 305 degrees at about 7 kt. The 
cyclone should continue to move northwestward today around the 
southwestern edge of a mid-level ridge. On Sunday, a turn back 
toward the west-northwest is anticipated as Sean continues to 
weaken into a more shallow vortex and thus will be steered by the 
low-level wind flow. How quickly Sean weakens will depict when the 
system turns back west-northwestwards. The NHC forecast is similar 
to the previous advisory and lies near the middle of the guidance 
envelope.

Sean is moving into an increasingly dry mid-level airmass, which is 
well depicted on GOES-16 water mid-level water vapor imagery. This 
more stable and dry environment should cause additional weakening 
during the next couple of days. Global models depict that Sean will 
struggle to produce deep convection by this evening and into Sunday. 
The time of the system degenerating into a remnant low has been 
moved up to 24 hours, but that could occur even sooner. The 
circulation is expected to open up into a trough in 60 hours, and 
dissipation is now indicated in the official forecast by that time.


FORECAST POSITIONS AND MAX WINDS
 
INIT  14/1500Z 16.0N  44.2W   30 KT  35 MPH
 12H  15/0000Z 16.6N  45.0W   30 KT  35 MPH
 24H  15/1200Z 17.2N  46.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 36H  16/0000Z 17.7N  48.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  16/1200Z 17.9N  50.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  17/0000Z...DISSIPATED
 
$$
Forecaster Kelly
 
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