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| #1246690 (Received by flhurricane at: 4:45 PM 30.Sep.2025) TCDAT4 Hurricane Imelda Discussion Number 17 NWS National Hurricane Center Miami FL AL092025 500 PM EDT Tue Sep 30 2025 The hurricane continues to gradually become better organized, with curved banding features becoming more prominent over the circulation. Deepest convection is noted over the western semicircle of the system with tops to near -70 deg C. Upper-level outflow is fairly well-defined at this time. The advisory intensity is set at 75 kt which is in line with flight-level wind observations from the previous Hurricane Hunter mission. Subjective and objective Dvorak estimates are a little lower. Another Air Force Reserve Unit aircraft is scheduled to investigate Imelda soon to check on the intensity and structure of the tropical cyclone. Imelda is moving a little faster toward the east-northeast with a motion estimate of 060/10 kt. A mid-tropospheric trough near the U.S. east coast should cause the hurricane to continue to accelerate east-northeastward over the next couple of days. The forecast track brings the center of the hurricane near Bermuda in less than 36 hours, with tropical storm conditions expected to reach Bermuda by tomorrow afternoon. There will likely be some binary interactions between Imelda and Humberto since the circulations of the two systems are getting very close together. However, it is difficult to specify how significantly this interaction will affect Imelda's track. The official forecast is near the southern edge of the model guidance suite. The hurricane is expected to be within an environment of moderate or stronger vertical wind shear, but in a favorable thermodynamic environment during the next day or so. An upper-level trough to the northwest of Imelda could contribute to strengthening due to baroclinic forcing and upper-level divergence while the system nears Bermuda. This could result in a fairly potent, if not an entirely tropical, cyclone passing near the island tomorrow. Later in the forecast period, the global models show the system merging with a broad baroclinic zone over the north Atlantic, and the simulated satellite imagery from these models takes on the appearance of an extratropical cyclone in 2-3 days. KEY MESSAGES: 1. Imelda is expected bring damaging hurricane-force-winds to Bermuda when it passes near or over that island by Wednesday afternoon or evening. A Hurricane Warning is in effect for Bermuda. 2. Imelda is likely to cause large and damaging waves in Bermuda. 3. Heavy rainfall could cause flash flooding across Bermuda Wednesday into Thursday. 4. Swells and high surf from both Humberto and Imelda are expected to produce dangerous marine conditions and rip currents along much of the East Coast of the United States during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 29.4N 75.5W 75 KT 85 MPH 12H 01/0600Z 30.0N 73.1W 80 KT 90 MPH 24H 01/1800Z 31.2N 68.7W 85 KT 100 MPH 36H 02/0600Z 32.8N 63.4W 85 KT 100 MPH 48H 02/1800Z 34.9N 56.7W 80 KT 90 MPH 60H 03/0600Z 38.0N 51.5W 70 KT 80 MPH...POST-TROP/EXTRATROP 72H 03/1800Z 40.4N 49.1W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 04/1800Z 45.5N 43.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 05/1800Z 52.5N 32.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch |
