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Tropical Storm Josephine Forecast Discussion Number 13
2020-08-14 22:36:07| National Hurricane Center (Atlantic)
Issued at 500 PM AST Fri Aug 14 2020 000 WTNT41 KNHC 142035 TCDAT1 Tropical Storm Josephine Discussion Number 13 NWS National Hurricane Center Miami FL AL112020 500 PM AST Fri Aug 14 2020 An Air Force Reserve Hurricane Hunter aircraft reported that the circulation of Josephine was still closed, and that the center was a little farther to the north than previously thought - possibly due to reformation close to a strong convective burst. The aircraft reported a minimum pressure of 1004 mb, and the combination of flight-level and SFMR winds support an initial intensity of 35 kt. Satellite imagery indicates that Josephine is encountering increasing westerly shear, with cirrus clouds west of the storm blowing into the cyclone. Aside from the nudge to the north, the initial motion is generally west-northwestward or 300/14 kt. There is again no change to the track forecast philosophy. Josephine should continue a west- northwestward motion as it approaches a weakness in the subtropical ridge in 48-60 h. Then, the cyclone should gradually turn northward and move through the weakness in 72-96 h. Late in the forecast period, Josephine or its remnants are expected to turn north-northeastward along the southern edge of the mid-latitude westerlies. Portions of the forecast track have been adjusted northward based mainly on the initial position, and the new forecast track lies close to the various consensus models. The increasing shear means that Josephine is just about out of time to intensify. The intensity forecast calls for a little strengthening tonight in case a convective burst causes some spin up. After that, the cyclone should weaken, with the new forecast showing it becoming a depression in 48 h and a remnant low by 96 hr. The global models continue to forecast a faster weakening, and there is still the alternative scenario that Josephine could decay to a tropical wave before 96 h. KEY MESSAGES: 1. Josephine should pass far enough to the northeast of the Leeward Islands over the weekend to prevent major impacts. However, interests there should continue to monitor its progress until the storm has passed north of that area. 2. Locally heavy rainfall is possible in the northern Leeward Islands, the Virgin Islands, and Puerto Rico as Josephine passes by to the northeast. Isolated minor flooding is possible in Puerto Rico through Monday. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 17.8N 56.1W 35 KT 40 MPH 12H 15/0600Z 18.6N 58.0W 40 KT 45 MPH 24H 15/1800Z 19.9N 60.5W 40 KT 45 MPH 36H 16/0600Z 21.1N 62.9W 35 KT 40 MPH 48H 16/1800Z 22.5N 65.1W 30 KT 35 MPH 60H 17/0600Z 24.1N 66.7W 30 KT 35 MPH 72H 17/1800Z 25.7N 67.7W 25 KT 30 MPH 96H 18/1800Z 28.6N 67.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 19/1800Z 32.1N 65.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Beven
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