Issued at 1100 PM AST Mon Sep 29 2025
000 WTNT43 KNHC 300256 TCDAT3 Hurricane Humberto Discussion Number 22 NWS National Hurricane Center Miami FL AL082025 1100 PM AST Mon Sep 29 2025 Northwesterly vertical wind shear is causing Humberto to lose strength tonight. Geostationary satellite and microwave images indicate that the cloud pattern has become asymmetric with the inner core now fragmented and located near the western edge of the cloud mass. The Air Force Hurricane Hunters have been investigating the hurricane over the past few hours and have found that the minimum pressure has increased to around 963 mb. The aircraft data also indicate that the maximum winds have lowered to around 100 kt. Humberto is moving north-northwestward at 12 kt on the southwest side of a subtropical ridge. The hurricane should turn northward on Tuesday as the ridge shifts east and weakens. On Wednesday, a mid- to upper-level trough is expected to amplify over the north Atlantic, causing Humberto to turn sharply to the northeast or east-northeast and accelerate. The models are in good agreement, and no significant changes were made to the previous forecast. This track takes the core of Humberto well west and then north of Bermuda. Continued steady weakening is expected as northwesterly vertical wind shear and intrusions of dry air persist over the next day or two. By late Wednesday, Humberto is expected to merge with a mid- to upper-level trough, and that should cause the system to develop frontal features and complete extratropical transition. Humberto is expected to grow significantly in size as it becomes extratropical. The large extratropical low in combination with Imelda will cause rough marine conditions over a large portion of the western and central Atlantic. See Key Messages below for more information. KEY MESSAGES: 1. Humberto's outer rainbands could produce gusty winds and heavy rainfall over Bermuda on Tuesday and Wednesday. Please follow local updates from the Bermuda Weather Service for impacts from both Humberto and Imelda. 2. Dangerous marine conditions, including high surf and life-threatening rip currents, will continue to affect beaches of the northern Caribbean, Bahamas, Bermuda, and much of the east coast of the United States through the week. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 30.1N 68.5W 100 KT 115 MPH 12H 30/1200Z 32.0N 68.8W 85 KT 100 MPH 24H 01/0000Z 34.4N 67.7W 75 KT 85 MPH 36H 01/1200Z 36.1N 64.5W 70 KT 80 MPH 48H 02/0000Z 37.4N 58.6W 70 KT 80 MPH...POST-TROP/EXTRATROP 60H 02/1200Z 39.8N 50.4W 65 KT 75 MPH...POST-TROP/EXTRATROP 72H 03/0000Z 43.4N 40.1W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 04/0000Z...DISSIPATED $$ Forecaster Cangialosi
