000 WTNT43 KNHC 041441 TCDAT3 Tropical Storm Leslie Discussion Number 9 NWS National Hurricane Center Miami FL AL132024 1100 AM AST Fri Oct 04 2024 A recent SSMIS microwave pass depicted that Leslie is continuing to become better organized and is trying to develop an inner core. Burst of deep convection have continued to develop mainly on the southern semi-circle as the system is still battling some deep-layer northeasterly wind shear. Given the improved convective pattern the subjective Dvorak intensity estimates have increased this cycle with a data-T 3.5/55 kt, from both TAFB and SAB. Using these estimates and the improving structure, the initial intensity is set to 55 kt for this advisory. Leslie is moving slowly westward at 280/5 kt, along the southern periphery of the subtropical ridge. The ridge will continue to steer Leslie, with a gradual turn west-northwestward then northwestward as it rounds the ridge. Leslie should continue north-westward with a slight increase in forward speed through the end of the forecast period. The NHC track forecast is very near the previous forecast track, which lies between the HCCA HFIP-corrected consensus and simple consensus aids. Northeasterly shear should begin to decrease later today as Hurricane Kirk continues to pull further away from the system. Strengthening is then forecast over the next 2-3 days with warm sea surface temperatures, upper-level divergence and low deep-layer shear. The intensity guidance, especially the peak has come down this cycle, and that is a combination of a few factors. In about 3 days, Leslie is forecast to move over the cold wake of Kirk, and encounter increasing dry air, mid-level shear, and the upper-level pattern also become a little less diffluent. This should cause the intensity of Leslie to plateau through the end of the forecast period. The NHC intensity forecast follows these trends and is slightly lower than the previous forecast, but lies near the higher end of the intensity guidance. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 10.0N 33.0W 55 KT 65 MPH 12H 05/0000Z 10.3N 34.0W 65 KT 75 MPH 24H 05/1200Z 10.8N 35.3W 75 KT 85 MPH 36H 06/0000Z 11.4N 36.6W 80 KT 90 MPH 48H 06/1200Z 12.4N 37.8W 80 KT 90 MPH 60H 07/0000Z 13.8N 39.3W 85 KT 100 MPH 72H 07/1200Z 15.3N 40.9W 90 KT 105 MPH 96H 08/1200Z 18.2N 44.4W 85 KT 100 MPH 120H 09/1200Z 20.9N 47.7W 85 KT 100 MPH $$ Forecaster Kelly