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| #1108165 (Received by flhurricane at: 5:30 AM 21.Sep.2022) TCDAT2 Hurricane Fiona Discussion Number 28 NWS National Hurricane Center Miami FL AL072022 500 AM EDT Wed Sep 21 2022 An Air Force Reserve Hurricane Hunter aircraft has recently reported 700-mb flight-level winds of 128 kt, and reliable surface winds estimates from the SFMR of 115 kt. The central pressure inside the 25 n mi wide eye has fallen to 939 mb. Based on these data, the initial intensity is set at 115 kt, making Fiona a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. There is little change to the intensity forecast philosophy since the last advisory. The vertical wind shear over Fiona is expected to remain low to moderate during the next couple of days. During that time, the hurricane will be traversing warm sea surface temperatures and remain in a moist environment. These conditions should allow for some additional strengthening during the next 12 to 24 hours, and the new intensity forecast calls for a peak intensity of 120 kt during that time. After that time, difficult- to-predict eyewall replacement cycles are likely to cause some fluctuations in intensity. Starting near 72 h, Fiona is expected to interact with a vigorous mid-latitude trough, which should lead to transition into an intense extratropical low between 72-96 h. After 96 h, the system is expected to weaken. The initial motion is now 360/7. Fiona should move generally northward around the western periphery of a mid-level ridge during the next 12-24 hours. After that time, the hurricane is forecast to turn north-northeastward and begin to gradually accelerate as the aforementioned trough approaches from the northwest. There were no no significant changes to the guidance from the last advisory, and the new forecast track is an update of the previous track. Key Messages: 1. Heavy rains south of Fiona will continue to impact the Turks and Caicos through this morning with additional flooding possible. 2. Tropical storm conditions are possible on Bermuda by late Thursday. 3. Fiona is expected to affect portions of Atlantic Canada as a powerful hurricane-force cyclone late Friday and Saturday, and could produce significant impacts from high winds, storm surge, and heavy rainfall. Interests in these areas should closely monitor the progress of Fiona and updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 21/0900Z 23.9N 71.8W 115 KT 130 MPH 12H 21/1800Z 25.0N 71.7W 120 KT 140 MPH 24H 22/0600Z 26.9N 71.1W 120 KT 140 MPH 36H 22/1800Z 29.3N 69.8W 120 KT 140 MPH 48H 23/0600Z 32.3N 67.4W 120 KT 140 MPH 60H 23/1800Z 36.5N 63.3W 115 KT 130 MPH 72H 24/0600Z 42.0N 60.9W 105 KT 120 MPH 96H 25/0600Z 50.0N 60.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 26/0600Z 56.0N 59.0W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven |
