Issued at 500 AM EDT Wed Oct 01 2025
000 WTNT44 KNHC 010855 TCDAT4 Hurricane Imelda Discussion Number 19 NWS National Hurricane Center Miami FL AL092025 500 AM EDT Wed Oct 01 2025 Imelda has continued to become better organized overnight with a more-defined eye and an increasingly symmetric inner core on satellite imagery. Data from an earlier Air Force Hurricane Hunter mission supported the previous 75-kt assessment with 82-kt flight-level winds and a central pressure near 976 mb. Since the aircraft departed, the satellite presentation has continued to improve, so the initial intensity is set slightly higher at 80 kt. The hurricane is accelerating towards the east-northeast, with the latest motion estimated to be 070/17 kt. A faster east-northeast motion is expected soon in the strong flow ahead of a large-scale trough over the western Atlantic. The 00 UTC guidance suite did provide some wrinkles to the forecast, with much of guidance showing an eastward motion later today as Imelda experiences northerly flow behind the approaching trough. This nudges the system farther south, with many aids south of Bermuda now after being more centered on the island 6h ago. At this point, the core of Bermuda is still expected to be close to the island late today, and residents should expect deteriorating conditions this afternoon. Beyond that point, the guidance spread becomes massive, with the ECMWF and GFS models about 1600 miles apart at day 5, dependent on whether the trough eventually picks up the hurricane or not. For now the GFS looks like an outlier solution so it won't be weighed much in this forecast, but the new NHC track is slower overall. Imelda is expected to continue to strengthen and grow in size while it approaches Bermuda as a category 2 hurricane. After it passes the islands, shear greatly increases, but Imelda should undergo a favorable trough interaction, keeping it producing hurricane-force for a couple more days as a powerful extratropical low. Imelda is also expected to cause the ongoing high surf and swells to persist over a large portion of the central and western Atlantic for the next several days due to the forecast size of the cyclone. The new intensity forecast is on the high side of the guidance, but a bit lower than the 00 UTC ECMWF model solution. KEY MESSAGES: 1. Imelda is expected to bring damaging hurricane-force winds when it passes near or over Bermuda late this afternoon or evening. A Hurricane Warning is in effect for the island. 2. Heavy rainfall could cause flash flooding across Bermuda later today into Thursday. Large and damaging waves are also expected on the island. 3. 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 01/0900Z 30.2N 72.1W 80 KT 90 MPH 12H 01/1800Z 31.1N 69.0W 85 KT 100 MPH 24H 02/0600Z 32.2N 64.0W 85 KT 100 MPH 36H 02/1800Z 33.4N 58.0W 80 KT 90 MPH...POST-TROPICAL 48H 03/0600Z 35.0N 53.0W 75 KT 85 MPH...POST-TROP/EXTRATROP 60H 03/1800Z 36.7N 50.5W 70 KT 80 MPH...POST-TROP/EXTRATROP 72H 04/0600Z 39.7N 48.4W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 05/0600Z 44.8N 41.3W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 06/0600Z 49.0N 33.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Blake
