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Hurricane Leslie Forecast Discussion Number 56
2018-10-10 10:34:34| National Hurricane Center (Atlantic)
Issued at 500 AM AST Wed Oct 10 2018 000 WTNT43 KNHC 100834 TCDAT3 Hurricane Leslie Discussion Number 56 NWS National Hurricane Center Miami FL AL132018 500 AM AST Wed Oct 10 2018 Geostationary satellite and microwave images indicate that Leslie has a large and ragged banded eye feature with deep convection most organized over the northern semicircle. Since the Dvorak classifications from TAFB and SAB are unchanged at 4.0/65 kt, the initial wind speed is held at that value. Leslie has another day or two to strengthen while it remains in low wind shear conditions and over marginally warm waters. After that time, an increase in shear and lower SSTs should cause Leslie to weaken. It is possible that Leslie could become a post-tropical cyclone by day 5, but confidence is not high on that occurring. The NHC intensity forecast is largely an update of the previous one and it lies at the high end of the model guidance. Leslie is now moving southward at 9 kt in the flow on the southwest side of a broad mid- to upper-level trough. A slower south- southeastward motion is expected during the day today as the trough pulls away. A turn to the east-northeast is expected tonight as another trough approaches Leslie from the northwest, and that motion with an increase in forward speed is expected through early this weekend. After that time, the models are coming into better agreement in showing Leslie being left behind and moving southwestward on Sunday and Monday as a ridge builds to its northwest. The NHC track forecast is adjusted southward at days 3 to 5 to be closer to the latest consensus aids. Although the deterministic models are in better agreement this cycle, there is still a lot of spread in the GFS and ECMWF ensemble members and confidence in the track forecast remains fairly low. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 28.6N 42.6W 65 KT 75 MPH 12H 10/1800Z 28.0N 42.3W 70 KT 80 MPH 24H 11/0600Z 28.1N 40.9W 75 KT 85 MPH 36H 11/1800Z 29.1N 38.3W 80 KT 90 MPH 48H 12/0600Z 30.5N 34.2W 75 KT 85 MPH 72H 13/0600Z 31.5N 25.0W 70 KT 80 MPH 96H 14/0600Z 30.5N 21.5W 50 KT 60 MPH 120H 15/0600Z 28.5N 23.5W 40 KT 45 MPH $$ Forecaster Cangialosi
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