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| #1108627 (Received by flhurricane at: 11:09 PM 23.Sep.2022) TCDAT2 Post-Tropical Cyclone Fiona Discussion Number 39 NWS National Hurricane Center Miami FL AL072022 1100 PM AST Fri Sep 23 2022 Satellite images and observations from an Air Force Hurricane Hunter aircraft indicate that Fiona is now an intense extratropical cyclone. The system`s appearance has evolved into a comma-shaped cloud pattern with a frontal band extending well to the south and southwest. Data from the Hurricane Hunters indicate that the radius of maximum winds is on the order of 100 miles or more. Although the minimum central pressure is a very low 933 mb, the maximum winds have decreased to near 90 kt. The cyclone has been moving very rapidly northward or around 360/40 kt on the eastern side of a deep-layer trough. Fiona should slow its forward speed while it interacts with the trough during the next couple of days. The official track forecast has been adjusted a little to the west of the previous one for the next 12-24 hours, and is on the western side of the track model suite. Fiona`s center should move over eastern Nova Scotia shortly, and then traverse the eastern Gulf of Saint Lawrence, eastern Labrador and move over the southeastern Labrador Sea. It should be repeated that strong winds, heavy rains, and storm surges are occurring well away from the center. Gradual weakening is anticipated during the next couple of day, and Fiona`s winds should drop below hurricane strength in 24 hours or so. The system should wind down to a marginal gale center after moving into the southeastern Labrador Sea, and the global models indicate that the system should dissipate to the west of Greenland in about 4 days. The official intensity forecast remains on the high end of the model guidance. Key Messages: 1. Fiona is expected to affect portions of Atlantic Canada as a powerful hurricane-force cyclone overnight, and significant impacts from high winds, storm surge, and heavy rainfall are expected. Hurricane and Tropical Storm Warnings are in effect for much of Atlantic Canada. 2. 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 northwestern Bahamas, Bermuda, and Atlantic Canada during the next couple of days. FORECAST POSITIONS AND MAX WINDS INIT 24/0300Z 44.5N 60.8W 90 KT 105 MPH...POST-TROPICAL 12H 24/1200Z 47.5N 60.7W 70 KT 80 MPH...POST-TROP/EXTRATROP 24H 25/0000Z 51.2N 60.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 36H 25/1200Z 54.6N 58.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 48H 26/0000Z 58.0N 57.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 60H 26/1200Z 60.6N 57.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 27/0000Z 63.0N 57.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 28/0000Z...DISSIPATED $$ Forecaster Pasch |
