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Post-Tropical Cyclone Leslie Forecast Discussion Number 70
2018-10-13 22:37:05| National Hurricane Center (Atlantic)
Issued at 500 PM AST Sat Oct 13 2018 000 WTNT43 KNHC 132036 TCDAT3 Post-Tropical Cyclone Leslie Discussion Number 70 NWS National Hurricane Center Miami FL AL132018 500 PM AST Sat Oct 13 2018 After a total of 70 advisories, long-lived Leslie has become post-tropical just west of the coast of Portugal, finally succumbing to the combination of cool waters, strong vertical wind shear, and interaction with an approaching cold front. The air mass ahead of the cyclone has moistened up in the low levels with Faro, Portugal, reporting a dewpoint of 70F/21C, but the dewpoints across central and northern Portugal ahead of Leslie are only in the low-60F range, which is not indicative of a tropical air mass. Thus, the cyclone is now a powerful post-tropical low pressure system that even has a partial eye noted in the most recent 2000Z Portuguese composite radar imagery. After landfall, rapid weakening is anticipated, and Leslie is forecast to degenerate into a broad low pressure area over or just north of Spain by late Sunday. Leslie is moving quickly toward the northeast or 050/30 kt. Post-tropical Cyclone Leslie should continue in a fast northeastward direction for the next 12-18 hours, making landfall near or just south of Porto, Portugal by 14/0000Z. This forecast motion is consistent with the previous advisory and the latest track model guidance. The meteorological services of Portugal and Spain are handling hazards information for their respective countries via local weather products. This is the last National Hurricane Center (NHC) advisory on this system. Key Messages: 1. Leslie is expected to bring near hurricane-force winds to portions of Portugal later tonight as a powerful post-tropical cyclone. Gale-force winds are also likely to affect portions of northwestern and northern Spain tonight and Sunday. 2. Leslie is expected to produce rainfall amounts of 25 to 75 mm (1 to 3 inches) with isolated amounts as high as 125 mm (5 inches) across portions of Portugal and Spain, which could cause flash flooding. 3. For more information on Leslie, interests in Portugal should refer to products from the Portuguese Institute for Sea and Atmosphere at www.ipma.pt. Interests in Spain should refer to products from the State Meteorological Agency at www.aemet.es. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 40.5N 9.5W 60 KT 70 MPH...POST-TROPICAL 12H 14/0600Z 43.0N 4.9W 35 KT 40 MPH...POST-TROPICAL INLAND 24H 14/1800Z...DISSIPATED $$ Forecaster Stewart
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