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#1157155 (Received by flhurricane at: 4:34 AM 13.Oct.2023) TCDAT4 Tropical Storm Sean Discussion Number 10 NWS National Hurricane Center Miami FL AL192023 500 AM AST Fri Oct 13 2023 Moderate westerly deep-layer shear continues over Sean this morning, and most of the associated deep convection is displaced to the east of Sean's center. Although the low-level circulation remains at least partially exposed in proxy-visible satellite images, new bursts of deep convection have recently developed closer to the center of Sean. It remains to be seen whether this activity will be persistent enough to support any additional strengthening. The latest objective and subjective satellite intensity estimates range from 30-45 kt, and a blend of these data support keeping the initial intensity at 40 kt. Sean is moving west-northwestward (285 degrees) at 11 kt. The general track forecast reasoning has not changed. Sean should move west-northwestward to northwestward over the next few days while being steered by a weak subtropical ridge over the eastern and central Atlantic. There are no significant changes noted in the latest track guidance. The updated NHC forecast lies slightly to the left of the previous prediction, primarily the result of a more west-northwestward initial motion based on recent center fixes. The various global and regional models suggest Sean is likely near or at its peak intensity. Although the shear could weaken some during the next couple of days, the convective structure of Sean is unlikely to improve much while the storm gains latitude and moves into a drier, more stable environment. The NHC forecast continues to show gradual weakening during the next few days, in good agreement with the latest multi-model consensus aids. The global models show an even faster rate of weakening, as the system becomes devoid of organized convection by early next week in both GFS and ECMWF model-simulated satellite imagery. Sean is still forecast to open into a trough and dissipate between 72-96 h. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 14.3N 40.5W 40 KT 45 MPH 12H 13/1800Z 15.1N 41.6W 40 KT 45 MPH 24H 14/0600Z 16.4N 42.9W 35 KT 40 MPH 36H 14/1800Z 17.6N 44.2W 35 KT 40 MPH 48H 15/0600Z 18.4N 45.3W 30 KT 35 MPH 60H 15/1800Z 19.2N 46.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 16/0600Z 19.7N 47.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 17/0600Z...DISSIPATED $$ Forecaster Reinhart |