Issued at 1100 AM AST Fri Aug 22 2025
542 WTNT45 KNHC 221439 TCDAT5 Hurricane Erin Discussion Number 45 NWS National Hurricane Center Miami FL AL052025 1100 AM AST Fri Aug 22 2025 Erin is now well into its extratropical transition. While there is some convection that has recently reformed near the center, all of its other convection has shifted on the left side, with noticeable frontal features in the northeastern quadrant. Additionally, the stratus and stratocumulus clouds off the Mid-Atlantic U.S. coast continue to suggest that cold air advection is occuring in the hurricane's wake. The initial intensity is kept at 80 kt pending receipt of the full late-morning scatterometer data, though the partial pass suggested Erin had grown even larger. The hurricane is moving faster to the east-northeast, now estimated at 24 kt. Model guidance is rapidly accelerating Erin in that direction over the weekend, reaching a peak speed of up to 40 kt Sunday. The powerful extratropical low should slow down and could undergo a loop over the far North Atlantic early next week as it becomes a large occluded low. The new forecast is a bit faster and south of the previous one, based on the latest corrected consensus guidance from HCCA and Google Deep Mind. Current trends and model fields indicate that Erin should complete extratropical transition by tonight, with perhaps a slight weakening of the winds on Saturday. However, Erin is forecast to become an even larger and stronger system late Saturday into Sunday due to phasing with a mid-latitude trough, inducing baroclinic reintensification and even the development of a sting jet on the back side. While they disagree on the exact timing, the global models are all showing a 75-90 kt sting jet on Sunday. The new NHC forecast is raised during the extratropical phase for Sunday, and still could be too low if the latest ECMWF solution is correct. A steady weakening is likely to occur early next week as Erin occludes and loses its upper support south of Iceland. 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. Coastal flooding is expected at times of high tide along portions of the U.S. Mid-Atlantic and New England coasts through tonight, making some roads impassable. Large waves along the coast could also cause significant beach erosion and overwash. 3. Gale-force wind gusts are possible along the coast of Nova Scotia today and the Avalon Peninsula of Newfoundland on Saturday. FORECAST POSITIONS AND MAX WINDS INIT 22/1500Z 38.8N 63.1W 80 KT 90 MPH 12H 23/0000Z 40.4N 58.8W 80 KT 90 MPH...POST-TROP/EXTRATROP 24H 23/1200Z 42.3N 51.4W 75 KT 85 MPH...POST-TROP/EXTRATROP 36H 24/0000Z 45.5N 41.9W 75 KT 85 MPH...POST-TROP/EXTRATROP 48H 24/1200Z 49.6N 32.1W 80 KT 90 MPH...POST-TROP/EXTRATROP 60H 25/0000Z 52.9N 25.9W 80 KT 90 MPH...POST-TROP/EXTRATROP 72H 25/1200Z 55.9N 22.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 26/1200Z 58.1N 21.3W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 27/1200Z 56.5N 18.5W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Blake
NHC Atlantic
