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| #1154256 (Received by flhurricane at: 10:44 PM 23.Sep.2023) TCDAT1 Post-Tropical Cyclone Ophelia Discussion Number 11 NWS National Hurricane Center Miami FL AL162023 1100 PM EDT Sat Sep 23 2023 Ophelia appears to have lost its tropical characteristics. Surface observations show a well-defined wind shift associated with a frontal boundary extending across eastern Virginia, and the heaviest precipitation is now well north of the center, oriented along and to the north of the front. In addition, phase space diagrams based on global model fields indicate that the system has entered the asymmetric cold-core regime. Therefore, Ophelia is being declared a post-tropical cyclone. Surface observations indicate that maximum winds have decreased to 30 kt, mainly over the ocean well east of the center. With the last bit of convection having been sheared off to the north, the center appears to have slowed down since the last advisory, and the current estimate is northward at 360/7 kt. The circulation is expected to turn northeastward on Sunday, but also become more diffuse while it moves across eastern Virginia and the Delmarva Peninsula. The NHC forecast now shows the low becoming absorbed by the nearby frontal boundary by 36 hours. Maximum winds are likely to remain around 30 kt until dissipation, mainly in a band to the north of the front off the coast of Long Island. This is the last tropical cyclone discussion issued by the National Hurricane Center on Ophelia. Future information on Ophelia can be found in discussions issued by the Weather Prediction Center beginning at 500 AM EDT, under AWIPS header TCDAT1, WMO header WTNT41 KWNH, and on the web at www.hurricanes.gov. Key Messages: 1. Coastal flooding will continue along portions of Chesapeake Bay and its tidal rivers through Sunday. Refer to statements from your local National Weather Service Forecast Office for additional information. 2. Heavy rainfall from Ophelia may produce localized flash and urban flooding impacts across portions of the Mid-Atlantic states from Virginia to New Jersey through Sunday. 3. Swells generated by Ophelia will affect much of the U.S. east coast through the weekend, likely causing life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 24/0300Z 37.1N 77.6W 30 KT 35 MPH...POST-TROP/EXTRATROP 12H 24/1200Z 38.2N 77.1W 30 KT 35 MPH...POST-TROP/EXTRATROP 24H 25/0000Z 39.1N 75.7W 30 KT 35 MPH...POST-TROP/EXTRATROP 36H 25/1200Z...DISSIPATED $$ Forecaster Berg |
