Hurricane Leslie Forecast Discussion Number 33
Issued at 1100 AM AST Thu Oct 10 2024 000 WTNT43 KNHC 101433 TCDAT3 Hurricane Leslie Discussion Number 33 NWS National Hurricane Center Miami FL AL132024 1100 AM AST Thu Oct 10 2024 The satellite presentation of Leslie has degraded since the previous advisory. Strong northerly wind shear has been pushing most of the convection to the south side of the low-level center. The most recent GOES-16 images suggest that the low-level center is likely just barely underneath the northern edge of the central dense overcast. The latest subjective current intensity values from TAFB and SAB are still 90 kt due to continuity constraints, but the latest ADT and AiDT intensity estimates from UW-CIMSS have decreased down to 72 kt. The intensity is set to 80 kt, as a blend of all the estimates. Leslie has already entered the strong northerly shear zone that has been advertised in previous discussions, and the guidance indicates that the shear will continue to increase to over 40 kt over the next 12 to 24 h. Shear that strong, combined with the dry environment that Leslie is embedded within, is likely to lead to steady to rapid weakening. The NHC forecast calls for Leslie to weaken by 35 kt over the next 36 h, in good agreement with the HCCA corrected consensus, HAFS models, and the intensity consensus. After that, the models hold on to Leslie, and there is quite a bit of uncertainty in the timing of when Leslie will become post-tropical. GFS and ECMWF simulated satellite imagery indicate that puffs of convection could continue through the weekend. The cyclone is also likely to interact with an approaching frontal system by Sunday. The NHC forecast continues to call for Leslie to become post-tropical by day 3. The initial motion is estimated to be west-northwestward, or 300/6 kt. Model guidance is in excellent agreement that a northward turn will happen very soon as Leslie moves around the southwestern periphery of a subtropical ridge over the eastern Atlantic. On Friday and Friday night, the hurricane should speed up and turn to the northeast, followed by an east-northeastward turn as it accelerates further over the weekend. The latest NHC track forecast is slightly west of the previous one during the first 48 hours of the forecast, and nearly identical to the previous forecast thereafter. The official forecast is in best agreement with the TVCA consensus. FORECAST POSITIONS AND MAX WINDS INIT 10/1500Z 23.2N 50.4W 80 KT 90 MPH 12H 11/0000Z 24.0N 50.9W 70 KT 80 MPH 24H 11/1200Z 25.7N 50.6W 55 KT 65 MPH 36H 12/0000Z 28.1N 48.9W 45 KT 50 MPH 48H 12/1200Z 30.8N 45.9W 45 KT 50 MPH 60H 13/0000Z 33.3N 41.0W 45 KT 50 MPH 72H 13/1200Z 35.2N 35.6W 45 KT 50 MPH...POST-TROPICAL 96H 14/1200Z 36.6N 25.9W 35 KT 40 MPH...POST-TROPICAL 120H 15/1200Z...DISSIPATED $$ Forecaster Hagen
Issued at 1100 AM AST Thu Oct 10 2024
000 WTNT43 KNHC 101433 TCDAT3 Hurricane Leslie Discussion Number 33 NWS National Hurricane Center Miami FL AL132024 1100 AM AST Thu Oct 10 2024 The satellite presentation of Leslie has degraded since the previous advisory. Strong northerly wind shear has been pushing most of the convection to the south side of the low-level center. The most recent GOES-16 images suggest that the low-level center is likely just barely underneath the northern edge of the central dense overcast. The latest subjective current intensity values from TAFB and SAB are still 90 kt due to continuity constraints, but the latest ADT and AiDT intensity estimates from UW-CIMSS have decreased down to 72 kt. The intensity is set to 80 kt, as a blend of all the estimates. Leslie has already entered the strong northerly shear zone that has been advertised in previous discussions, and the guidance indicates that the shear will continue to increase to over 40 kt over the next 12 to 24 h. Shear that strong, combined with the dry environment that Leslie is embedded within, is likely to lead to steady to rapid weakening. The NHC forecast calls for Leslie to weaken by 35 kt over the next 36 h, in good agreement with the HCCA corrected consensus, HAFS models, and the intensity consensus. After that, the models hold on to Leslie, and there is quite a bit of uncertainty in the timing of when Leslie will become post-tropical. GFS and ECMWF simulated satellite imagery indicate that puffs of convection could continue through the weekend. The cyclone is also likely to interact with an approaching frontal system by Sunday. The NHC forecast continues to call for Leslie to become post-tropical by day 3. The initial motion is estimated to be west-northwestward, or 300/6 kt. Model guidance is in excellent agreement that a northward turn will happen very soon as Leslie moves around the southwestern periphery of a subtropical ridge over the eastern Atlantic. On Friday and Friday night, the hurricane should speed up and turn to the northeast, followed by an east-northeastward turn as it accelerates further over the weekend. The latest NHC track forecast is slightly west of the previous one during the first 48 hours of the forecast, and nearly identical to the previous forecast thereafter. The official forecast is in best agreement with the TVCA consensus. FORECAST POSITIONS AND MAX WINDS INIT 10/1500Z 23.2N 50.4W 80 KT 90 MPH 12H 11/0000Z 24.0N 50.9W 70 KT 80 MPH 24H 11/1200Z 25.7N 50.6W 55 KT 65 MPH 36H 12/0000Z 28.1N 48.9W 45 KT 50 MPH 48H 12/1200Z 30.8N 45.9W 45 KT 50 MPH 60H 13/0000Z 33.3N 41.0W 45 KT 50 MPH 72H 13/1200Z 35.2N 35.6W 45 KT 50 MPH...POST-TROPICAL 96H 14/1200Z 36.6N 25.9W 35 KT 40 MPH...POST-TROPICAL 120H 15/1200Z...DISSIPATED $$ Forecaster Hagen
