Official Discussion issued by the National Hurricane Center

Sean (AL192023) DATA RELEASED: 10/11/2023 9:00:00 PM UTC

Copy of official data

Tropical Storm Sean Discussion Number   4
NWS National Hurricane Center Miami FL       AL192023
500 PM AST Wed Oct 11 2023

Sean remains poorly organized this afternoon. Satellite images show 
a ragged convective pattern with the low-level center located on the 
west side of a fragmented curved band, a bit more north than 
previously estimated. The Dvorak estimates remain steady at T2.5/35 
kt, so the initial intensity is held at 35 kt. However, as mentioned 
this morning, this wind speed estimate could be a little generous 
based on the earlier ASCAT pass.

The storm is currently experiencing moderate to strong southwesterly 
wind shear, and may only have a brief opportunity to strengthen  
over the next couple of days before it moves into an environment of 
drier air by the end of the week. Over the weekend, another round of 
shear should cause Sean to ultimately weaken and then degenerate 
into a remnant low in 4 to 5 days. The NHC intensity forecast has 
not changed much from the previous advisory and is within the 
guidance envelope.

Sean is moving west-northwestward at about 11 kt, and is expected to 
continue moving in this general direction over the next day or two. 
After 48 hours, the storm will begin to turn to the northwest as it 
moves along the southwestern portion of a mid-level ridge to its 
northeast. Over the weekend, a turn back to the west-northwest or 
west is anticipated as a low- to mid-level ridge re-establishes 
itself to the north of Sean and it becomes a more shallow cyclone. 
The NHC track forecast has been shifted northward of the previous 
one over the entire forecast period based on the initial position 
and subsequent model guidance.


INIT  11/2100Z 11.6N  35.3W   35 KT  40 MPH
12H  12/0600Z 12.1N  36.5W   35 KT  40 MPH
24H  12/1800Z 12.7N  38.1W   40 KT  45 MPH
36H  13/0600Z 13.4N  39.7W   40 KT  45 MPH
48H  13/1800Z 14.3N  41.1W   40 KT  45 MPH
60H  14/0600Z 15.3N  42.3W   35 KT  40 MPH
72H  14/1800Z 16.4N  43.6W   35 KT  40 MPH
96H  15/1800Z 18.1N  46.1W   30 KT  35 MPH
120H  16/1800Z 18.7N  50.2W   30 KT  35 MPH...POST-TROP/REMNT LOW

Forecaster Camposano/Cangialosi