Issued at 1100 AM AST Sat Sep 29 2018 245 WTNT43 KNHC 291446TCDAT3Subtropical Storm Leslie Discussion Number 13NWS National Hurricane Center Miami FL AL1320181100 AM AST Sat Sep 29 2018Leslie's cloud pattern has taken on a more tropical appearancesince last night. However, the cyclone is still co-located with anupper-level low, so its status as a subtropical cyclone ismaintained for this advisory. The initial intensity remains 40 kt,based on a subtropical classification of 35-40 kt from TAFB.The global models forecast that Leslie will separate from theupper-level low over the course of the next day or so, which shouldcomplete its transition to a tropical cyclone. While this couldresult in a short-term increase in shear over Leslie, by early nextweek the cyclone will likely be located within a fairly low shearenvironment. However, Leslie is expected to move very slowly by thattime, and ocean upwelling could limit or prevent furtherstrengthening. There is a large amount of spread in the intensityguidance by day 5, but it is worth noting that the models mostcapable of properly representing the effect of ocean cooling onintensity, COAMPS-TC, HWRF, and HMON, all keep Leslie belowhurricane strength for the next 5 days. The HWRF in particularforecasts nearly 5 deg C of ocean cooling beneath the cyclone. TheNHC intensity forecast is generally a little lower than the previousadvisory, but is still near the IVCN and HCCA consensus aids at allforecast hours. If Leslie moves more than expected, it would not besurprising if it strengthened more than currently forecast.Little change was made to the official track forecast. Leslie isstill expected to move slowly southwestward for the next couple ofdays, before coming to a near halt early next week. By themiddle of the week, an approaching mid-latitude trough could steerLeslie toward the north or northeast and allow the cyclone to startgaining speed, however, there is a lot of spread among the globalmodels as to how quickly this will occur, and confidence in thisportion of the forecast is fairly low.Large swells generated by Leslie when it was a strong extratropicallow will affect Bermuda, the east coast of the United States, andmost of the Greater and Lesser Antilles through the weekend. Theseswells could cause life-threatening surf and rip currents.FORECAST POSITIONS AND MAX WINDSINIT 29/1500Z 34.4N 50.8W 40 KT 45 MPH 12H 30/0000Z 33.8N 51.7W 45 KT 50 MPH 24H 30/1200Z 33.3N 52.7W 45 KT 50 MPH 36H 01/0000Z 33.1N 53.5W 50 KT 60 MPH...TROPICAL CYCLONE 48H 01/1200Z 32.8N 54.0W 50 KT 60 MPH 72H 02/1200Z 31.6N 55.0W 55 KT 65 MPH 96H 03/1200Z 31.0N 55.5W 60 KT 70 MPH120H 04/1200Z 33.0N 55.0W 65 KT 75 MPH$$Forecaster Zelinsky

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