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| #1242431 (Received by flhurricane at: 4:45 AM 22.Aug.2025) TCDAT5 Hurricane Erin Discussion Number 44 NWS National Hurricane Center Miami FL AL052025 500 AM AST Fri Aug 22 2025 Erin has begun extratropical transition. The center is now exposed to the southwest of the remaining central deep convection due to 30-35 kt of southwesterly shear. In addition, the hurricane has developed an expansive cirrus shield to the north, and stratus and stratocumulus clouds off the Mid-Atlantic U.S. coast suggest that cold air advection is occuring in the hurricane's wake. Based on the degradation of the satellite presentation since the previous full advisory, the initial intensity is lowered to 80 kt. The wind field continues to grow, and tropical-storm-force winds now extend as far as 320 n mi from the center. The hurricane has been moving northeastward, or 055/19 kt. Erin will accelerate toward the east-northeast, embedded within the mid-latitude westerlies, reaching a peak speed of about 35 kt in 48 hours. A significant reduction in forward speed is then expected on days 3 through 5 as the cyclone becomes cut off from the westerlies, stalling or meandering just south of Iceland by the middle of next week. The NHC track forecast is close to a blend of the GFS, ECMWF, and HCCA models, and no significant changes were made from the previous forecast. Global model thermal fields, model-simulated satellite imagery, and phase-space diagrams indicate that Erin should become post-tropical by 24 hours. The NHC intensity forecast generally follows a blend of the GFS and ECMWF surface wind fields, showing only some weakening during the next 36-48 hours. Global models are in good agreement that the post-tropical cyclone will phase with an upper-level trough in 48-60 hours, inducing baroclinic reintensification and possibly the development of a sting jet on the back side of the low. The NHC official forecast shows that strengthening at 60 hours. Steady weakening, and even more broadening of the wind field, should occur on days 3 through 5 as the low becomes vertically stacked 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. Gusts to gale force are possible along the coast of Nova Scotia today and the Avalon Peninsula of Newfoundland on Saturday. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 38.6N 65.3W 80 KT 90 MPH 12H 22/1800Z 39.9N 61.6W 80 KT 90 MPH 24H 23/0600Z 41.8N 55.2W 75 KT 85 MPH...POST-TROP/EXTRATROP 36H 23/1800Z 44.1N 47.3W 70 KT 80 MPH...POST-TROP/EXTRATROP 48H 24/0600Z 47.4N 38.4W 70 KT 80 MPH...POST-TROP/EXTRATROP 60H 24/1800Z 50.8N 30.6W 75 KT 85 MPH...POST-TROP/EXTRATROP 72H 25/0600Z 53.9N 24.8W 65 KT 75 MPH...POST-TROP/EXTRATROP 96H 26/0600Z 58.0N 20.9W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 27/0600Z 58.2N 20.1W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg |
