000 WTNT43 KNHC 122036 TCDAT3 Hurricane Leslie Discussion Number 66 NWS National Hurricane Center Miami FL AL132018 500 PM AST Fri Oct 12 2018 Leslie remains a well organized tropical cyclone, with a fairly symmetric central dense overcast, and hints of an eye in both conventional and microwave satellite imagery. A 1738 UTC SSMIS microwave overpass shows that there is some northeast to southwest tilt, due to an increase in westerly shear. Some slight weakening is foreast tonight while Leslie moves over cool SSTs of 23 to 24 degrees Celsius and into an area of increasing westerly shear. However, Leslie is forecast to transition into a powerful hurricane- force post-tropical cyclone in about 24 hours as it interacts with an approaching trough. The post-tropical cyclone is expected to make landfall along the west coast of the Iberian Peninsula shortly thereafter, and it should weaken due to land interaction after that time. The system is forecast to dissipate inland by Monday. Leslie continues to race across the far eastern Atlantic, with an initial motion estimate of 070/30 kt. The global models are now unanimous in taking Leslie quickly east-northeastward on the south side of a strong longwave trough over the northeast Atlantic. The official track foreast as been adjusted northward and is significantly faster than before, and brings the center of Leslie over the coast of the Iberian Peninsula by 0000 UTC Sunday. The system is likely to dissipate over the high terrain of Spain within a couple of days, but a 48-h forecast point is shown for continuity. Now that the track guidance is in much better agreement, confidence in the NHC track forecast has increased. After coordination with the meteorological services of Portugal and Spain, they have decided to provide information on the wind hazard with local products. Key Messages: 1. Leslie is expected to bring near hurricane-force winds on Saturday to portions of Portugal as a powerful post-tropical cyclone. Tropical-storm-force winds are also likely to affect portions of western Spain. 2. Leslie is expected to produce rainfall amounts of 25 to 75 mm (1 to 3 inches) with isolated amounts as high as 100 mm (4 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 12/2100Z 33.9N 24.1W 75 KT 85 MPH 12H 13/0600Z 35.6N 18.8W 70 KT 80 MPH 24H 13/1800Z 38.0N 12.0W 65 KT 75 MPH...POST-TROPICAL 36H 14/0600Z 40.6N 6.5W 45 KT 50 MPH...POST-TROPICAL/INLAND 48H 14/1800Z 43.0N 2.0W 30 KT 35 MPH...POST-TROPICAL/INLAND 72H 15/1800Z...DISSIPATED $$ Forecaster Brown