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| #1108440 (Received by flhurricane at: 11:12 PM 22.Sep.2022) TCDAT2 Hurricane Fiona Discussion Number 35 NWS National Hurricane Center Miami FL AL072022 1100 PM AST Thu Sep 22 2022 Fiona`s satellite appearance looks a little more asymmetric this evening, with deep convection and upper-level outflow becoming more restricted on the western side. That said, the hurricane has not yet lost any intensity. An Air Force Reserve Hurricane Hunter mission measured a peak 700-mb flight-level wind of 123 kt and SFMR winds as high as 110 kt, which support maintaining a 115-kt intensity on this advisory. In addition, dropsonde data indicate that the central pressure has fallen further to 932 mb, and the SFMR instrument measured hurricane-force winds now extending 100 n mi to the southeast of the center. The hurricane is still accelerating toward the north-northeast with an initial motion estimate of 030/18 kt. Fiona is getting closer to a deep-layer trough currently located over the northeastern United States, and this feature is expected to cause the hurricane to speed up further during the next day or so, reaching peak speeds of 30-35 kt by 24 hours as it approaches Nova Scotia. Fiona should merge with the trough soon after 24 hours, slow down a bit, but continue moving northward across Atlantic Canada to the Labrador Sea. The previous official forecast appears on track based on the latest guidance, and no significant changes were made to the new forecast. Fiona is forecast to remain over warm waters, including within the Gulf Stream current, during the next 24 hours, although deep-layer shear is forecast to increase substantially in 12-24 hours. Given the hurricane`s current appearance, some gradual weakening is anticipated during the next day or so. Extratropical transition should begin on Friday, and that process is expected to be quick, with Fiona becoming a warm-seclusion-type extratropical low Friday night before the center reaches Nova Scotia. Although continued weakening is forecast thereafter, Fiona is expected to maintain hurricane-force winds through 48 hours while it moves across the Gulf of St. Lawrence. Winds could drop below gale force by day 5 when the post-tropical low is over the Labrador Sea. After 24 hours, the NHC intensity forecast is a blend of the GFS and ECMWF global model solutions. Key Messages: 1. Hurricane conditions are expected on Bermuda overnight. Conditions should diminish below tropical storm force during the day on Friday. 2. Fiona is expected to affect portions of Atlantic Canada as a powerful hurricane-force cyclone late Friday and Saturday, and significant impacts from high winds, storm surge, and heavy rainfall are likely. Hurricane and Tropical Storm Warnings have now been issued for much of Atlantic Canada. 3. Large swells generated by Fiona are expected to cause life-threatening surf and rip current conditions along much of the east coast of the United States, the Bahamas, Bermuda, and Atlantic Canada during the next few days. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 31.9N 68.1W 115 KT 130 MPH 12H 23/1200Z 34.8N 65.4W 110 KT 125 MPH 24H 24/0000Z 40.9N 61.9W 105 KT 120 MPH 36H 24/1200Z 45.8N 61.0W 90 KT 105 MPH...POST-TROP/EXTRATROP 48H 25/0000Z 48.7N 60.1W 65 KT 75 MPH...POST-TROP/EXTRATROP 60H 25/1200Z 52.2N 58.6W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 26/0000Z 56.2N 57.9W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 27/0000Z 62.0N 57.7W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 28/0000Z 64.8N 56.2W 30 KT 35 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg |
