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| #980916 (Received by flhurricane at: 11:09 AM 04.Sep.2019) TCDAT5 Hurricane Dorian Discussion Number 45 NWS National Hurricane Center Miami FL AL052019 1100 AM EDT Wed Sep 04 2019 Satellite imagery indicates that the cloud tops in the eyewall of Dorian have cooled significantly during the past few hours, with the eye becoming better defined in NOAA Doppler radar data. However, just-received reports from an Air Force Reserve Hurricane Hunter aircraft show that the hurricane has changed little in intensity, with maximum winds remaining near 90 kt and the central pressure near 964 mb. The aircraft data show that hurricane-force winds are roughly 50 n mi offshore of the northeastern Florida peninsula, while surface observations show that tropical-storm conditions are affecting portions of the coast of northeastern Florida. The initial motion is now 335/8. Dorian is moving around the western end of the subtropical ridge, and it should recurve northward and northeastward into the mid-latitude westerlies during the next 24-48 h. This motion should bring the center of Dorian near or over the coast of North Carolina during the 36-48 h period. After that time, the cyclone is forecast to accelerate northeastward into the Atlantic toward the Canadian Maritimes, with a quick northeastward motion continuing for the remainder of the cyclone`s life. The track guidance is very tightly clustered, and the new forecast track, which has only minor changes from the previous forecast, lies in the center of the guidance envelope near the consensus models. It should be noted that the track is close to and almost parallel to the coast of the southeastern United State, and any deviation to the left of the track could bring the center onshore anywhere in the Carolinas. Dorian is expected to remain in an environment of light to moderate vertical wind shear and warm sea surface temperatures during the next 48 h. As a result, the hurricane is expected to maintain Category 2 intensity as it passes near the southeastern United States coast. After 48 h, increasing shear and dry air entrainment should cause a weakening trend. Extratropical transition should begin near the 72 h time, and the cyclone is forecast to become a hurricane-force extratropical low by 96 h near or over Nova Scotia and Newfoundland. Since the NHC track prediction continues to take Dorian dangerously close to the southeast U.S. coast, all interests from northeast Florida to the Carolinas should remain vigilant to the possibility of experiencing destructive winds, flooding rains, and life- threatening storm surges from this hurricane. Key Messages: 1. Life-threatening storm surge and dangerous winds are expected along portions of the Florida east coast and the coasts of Georgia, South Carolina, North Carolina, regardless of the exact track of Dorian`s center. Water levels could rise well in advance of the arrival of strong winds. Residents in these areas should follow advice given by local emergency officials. 2. The risk of dangerous storm surge, wind, and rain impacts along portions of the Virginia coast and the southern Chesapeake Bay continues to increase. Residents in these areas should continue to monitor the progress of Dorian. 3. Flash flooding will become increasingly likely across coastal Georgia into the eastern Carolinas tonight into Friday. There is a high risk of flash flooding over coastal sections of the Carolinas, where significant, life-threatening, flash flooding is expected. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 29.8N 79.7W 90 KT 105 MPH 12H 05/0000Z 30.8N 80.0W 90 KT 105 MPH 24H 05/1200Z 31.9N 79.8W 85 KT 100 MPH 36H 06/0000Z 33.1N 78.6W 85 KT 100 MPH 48H 06/1200Z 34.8N 76.4W 85 KT 100 MPH 72H 07/1200Z 39.9N 68.2W 75 KT 85 MPH 96H 08/1200Z 47.5N 59.0W 70 KT 80 MPH...POST-TROP/EXTRATROP 120H 09/1200Z 55.0N 46.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven |
