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| #1246893 (Received by flhurricane at: 4:54 AM 02.Oct.2025) TCDAT4 Hurricane Imelda Discussion Number 23 NWS National Hurricane Center Miami FL AL092025 500 AM AST Thu Oct 02 2025 The center of Imelda passed just south of Bermuda a few hours ago, with sustained hurricane force winds reported at one of the elevated stations there. Since then, the cyclone has continued to produce a central convective feature, and radar data from Bermuda shows fragments of spiral bands to the north of the center. Overall, it appears that Imelda is continuing through extratropical transition, but the process is not finished yet. Satellite intensity estimates have decreased, and based on these the initial intensity is lowered to a possibly generous 75 kt. The initial motion remains quickly east-northeastward or 075/26 kt. This general motion is likely to continue for the next 12-24 h. After that, the cyclone should phase with a digging mid-latitude trough that is currently north of the system, with this trough eventually becoming a deep-layer cut-off low over Imelda's low-level center. This evolution should cause the surface center to move generally northeastward from 24-72 h with a decrease in forward speed. An east-northeastward motion is expected by the end of the forecast period as the cyclone gets more embedded in the mid-latitude flow. The new forecast track is similar to the previous track through 72 h, and then is slower than and south of the previous track at 96 and 120 h. Current trends and global model guidance suggest that Imelda should complete extratropical transition later today. Phasing with the above-mentioned mid-latitude trough should help the system maintain its intensity for the next 3-4 days, and the intensity forecast has been nudged upward a bit to match a blend of the global model wind forecasts. After 96 h, the global models forecast the system to weaken quickly as the surface low separates from the upper-level center, and this is also reflected in the new intensity forecast. KEY MESSAGES: 1. Imelda's core has passed Bermuda, and conditions on the island are improving. However, tropical storm conditions are expected to continue for a few more hours. 2. The threat of heavy rainfall on Bermuda has diminished. 3. Swells and high surf from Imelda are expected to produce dangerous marine conditions and rip currents along much of the East Coast of the United States and the western Atlantic during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 32.8N 61.9W 75 KT 85 MPH 12H 02/1800Z 33.5N 57.7W 70 KT 80 MPH...POST-TROP/EXTRATROP 24H 03/0600Z 35.0N 52.9W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 03/1800Z 37.2N 50.2W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 04/0600Z 39.8N 48.3W 55 KT 65 MPH...POST-TROP/EXTRATROP 60H 04/1800Z 42.8N 45.7W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 05/0600Z 45.8N 41.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 06/0600Z 49.2N 32.6W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 07/0600Z 50.8N 25.8W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven |
