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WTNT44 KNHC 132038

TCDAT4

 

Tropical Storm Sean Discussion Number  12

NWS National Hurricane Center Miami FL       AL192023

500 PM AST Fri Oct 13 2023

 

Sean's satellite appearance continues to deteriorate this afternoon. 

Convection has waned with warming cloud tops to the east of the 

exposed low-level center. Sean is noticeably struggling with drier 

air impacting the system and the continued westerly wind shear. Any 

convection that tries to develop near the center is sheared off and 

dissipates. Satellite intensity estimates this afternoon range from 

25 to 40 kt. The initial intensity is held at 35 kt for this 

advisory, but this could be generous given the waning convection the 

last several hours.

 

As Sean moves through the drier and more stable airmass, further 

weakening is anticipated. Simulated satellite from the ECMWF and GFS 

depict that Sean may have occasional burst of convection the next 

day or so, but will continue to become less organized. This should 

cause Sean to become a post-tropical remnant low this weekend. 

However, recent trends suggest this could occur as early as 

tomorrow. The NHC intensity forecast is similar to the previous 

advisory, near the consensus intensity aids. 

 

The tropical storm has continued to move west-northwestward today, 

around 290 at 10 kt. A turn northwestward has been forecast to occur 

today, but the center has continued west-northwestward, which has 

resulted in a westward shift of the NHC forecast track. The forecast 

still calls for the northwestward motion to begin later this evening 

and continue over the next day or so. As Sean becomes a remnant low 

and further weakens, the system will turn more west-northwestward 

again and dissipate into an open trough in a few days.



 

FORECAST POSITIONS AND MAX WINDS

 

INIT  13/2100Z 14.9N  42.5W   35 KT  40 MPH

 12H  14/0600Z 15.8N  43.6W   30 KT  35 MPH

 24H  14/1800Z 16.9N  44.7W   30 KT  35 MPH

 36H  15/0600Z 17.7N  45.8W   25 KT  30 MPH...POST-TROP/REMNT LOW

 48H  15/1800Z 18.4N  47.2W   25 KT  30 MPH...POST-TROP/REMNT LOW

 60H  16/0600Z 18.8N  48.7W   25 KT  30 MPH...POST-TROP/REMNT LOW

 72H  16/1800Z...DISSIPATED

 

$$

Forecaster Kelly