Official Discussion issued by the National Hurricane Center
Leslie (AL132024) DATA RELEASED: 10/4/2024 9:00:00 AM UTC
Copy of official data Tropical Storm Leslie Discussion Number 8 NWS National Hurricane Center Miami FL AL132024 500 AM AST Fri Oct 04 2024 A 0421 UTC GMI microwave pass showed that Leslie has developed a well-defined low-level structure, along with what appears to be an attempt at an eyewall feature south of the center. This asymmetry in the convection is the result of continued moderate shear out of the north-northeast. ASCAT-C data from several hours ago showed several 44-kt wind barbs northwest of the center. Given the typical undersampling of this instrument, and the storm's improved structure despite the shear, the initial intensity is estimated to be 50 kt. The GMI and ASCAT passes helped immensely in locating Leslie's center, which is a little farther south than previously estimated. Leslie is moving slowly westward, or 270/5 kt, along the southern periphery of the subtropical ridge. With the ridge expected to remain centered over the eastern Atlantic, Leslie is forecast to gradually turn west-northwestward later today and then toward the northwest in about 48 hours, with that motion continuing through the middle of next week. The NHC track forecast is near a blend of the HCCA and TVCA consensus aids, and any differences from the previous prediction should be considered negligible. The deep-layer shear affecting Leslie is likely to abate in about 12 hours. However, there are a few environmental features that could potentially limit Leslie's rate of intensification. Mid-level shear and dry air are shown to be the biggest negative factors in the SHIPS diagnostics, and Leslie may end up moving over Hurricane Kirk's cold wake. Additional strengthening is still anticipated, however much of the intensity guidance has come down on this cycle. The NHC intensity forecast is slightly lower than the previous forecast to follow this trend, but it lies near or above the highest intensity models for most of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 9.8N 32.5W 50 KT 60 MPH 12H 04/1800Z 10.1N 33.4W 55 KT 65 MPH 24H 05/0600Z 10.5N 34.7W 60 KT 70 MPH 36H 05/1800Z 11.0N 36.1W 70 KT 80 MPH 48H 06/0600Z 11.8N 37.3W 75 KT 85 MPH 60H 06/1800Z 13.0N 38.6W 80 KT 90 MPH 72H 07/0600Z 14.5N 40.1W 85 KT 100 MPH 96H 08/0600Z 17.5N 43.6W 90 KT 105 MPH 120H 09/0600Z 20.3N 47.2W 95 KT 110 MPH $$ Forecaster Berg |