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Hurricane Erin Forecast Discussion Number 41
2025-08-21 16:44:57| National Hurricane Center (Atlantic)
Issued at 1100 AM EDT Thu Aug 21 2025 000 WTNT45 KNHC 211444 TCDAT5 Hurricane Erin Discussion Number 41 NWS National Hurricane Center Miami FL AL052025 1100 AM EDT Thu Aug 21 2025 Erin remains a sprawling hurricane, with its tropical-storm-force winds extending nearly 500 n mi across. In fact, comparing Erin with systems around the same intensity and in similar locations over the past couple of decades indicates that it is around the 90th percentile in size. The Air Force Hurricane Hunters indicate that the peak winds have come down a bit, and based on their data, the initial intensity is set at 85 kt. Although the core of Erin is pulling away from the United States, coastal flooding and tropical-storm-force winds continue along portions of the North Carolina and Virginia coasts. The center of Erin passed just east of NOAA buoy 41001 earlier this morning, and it reported a minimum pressure of 962 mb and a maximum significant wave height of 45 ft. The associated swells are covering nearly the entire western Atlantic from the Bahamas to Atlantic Canada. Erin is moving north-northeastward at 16 kt. A turn to the northeast or east-northeast with a significant increase in forward speed within the mid-latitude westerlies is expected to begin tonight, taking Erin out to sea over the north Atlantic during the next several days. The models are in good agreement, and only minor changes were made to the previous NHC forecast. Increasing southwesterly vertical wind shear, drier mid-level air, and cooler SSTs should cause Erin to gradually lose strength over the next several days. Extratropical transition is now expected to be complete by early Saturday, when the system is forecast to develop fronts after it crosses the north wall of the Gulf Stream. The NHC intensity forecast follows HCCA and IVCN in the short term, but leans toward the global model guidance during the predicted extratropical phase. KEY MESSAGES: 1. Erin will continue to produce life-threatening surf and rip currents along the beaches of the Bahamas, much of the east coast of the U.S., Bermuda, and Atlantic Canada during the next several days. Beachgoers in those areas should follow advice from lifeguards, local authorities, and beach warning flags. 2. Storm surge flooding and tropical storm conditions will continue on the North Carolina Outer Banks today. The storm surge will be accompanied by large waves, leading to significant beach erosion and overwash, making some roads impassible. 3. Tropical storm conditions are expected today along the Virginia coast. Wind gusts to tropical storm force are likely along portions of the remainder of the U.S. Mid-Atlantic and southern New England coasts today through early Friday. 4. Tropical storm conditions are possible on Bermuda this afternoon through early Friday. Gusts to gale force are possible along the coast of Nova Scotia on Friday and the Avalon Peninsula of Newfoundland on Saturday. FORECAST POSITIONS AND MAX WINDS INIT 21/1500Z 35.4N 70.9W 85 KT 100 MPH 12H 22/0000Z 37.0N 68.6W 80 KT 90 MPH 24H 22/1200Z 39.1N 64.5W 80 KT 90 MPH 36H 23/0000Z 41.0N 59.1W 75 KT 85 MPH 48H 23/1200Z 43.2N 51.7W 70 KT 80 MPH...POST-TROP/EXTRATROP 60H 24/0000Z 46.2N 43.7W 65 KT 75 MPH...POST-TROP/EXTRATROP 72H 24/1200Z 49.4N 35.7W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 25/1200Z 54.5N 25.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 26/1200Z 56.9N 21.1W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi
Category:Transportation and Logistics