Issued at 500 AM AST Thu Sep 25 2025
688 WTNT43 KNHC 250839 TCDAT3 Tropical Storm Humberto Discussion Number 3 NWS National Hurricane Center Miami FL AL082025 500 AM AST Thu Sep 25 2025 Humberto is still a shear tropical storm this morning. Deep convection is wrapped around the eastern side of the circulation with the low-level center mostly exposed to the west of the coldest cloud tops. Objective and subjective satellite Dvorak classifications have held steady this cycle, ranging from 33 to 41 kts. The initial intensity remains at 40 kt based on the scatterometer data mentioned in the previous discussion. The estimated motion is northwestward at 9 kt. Humberto is expected to be steered along the southern and southwestern side of a subtropical ridge centered over the western Atlantic. The track forecast becomes more complicated in the next few days due to the proximity of the tropical storm to 94L, the developing system to the west. Global models generally show Humberto moving around the western periphery of the subtropical high by the end of the forecast period, however there is quite a bit of uncertainty in the timing and location at which the storm will make that turn. The GFS and UKMet show a much faster and farther east track while the ECMWF predicts a slower and more westward track. The latest official track forecast is slower and a bit west of the previous prediction, near the center of the guidance envelope. Humberto is expected to gradually strengthen during the next couple of days, despite the strong-to-moderate vertical wind shear. When the westerly shear relaxes over the storm in 2-3 days, more signification intensification is expected over the warm ocean waters. Most model guidance predicts Humberto will reach hurricane strength over the weekend and become a major hurricane by early next week. Few changes have been made to the NHC intensity forecast, which still lies near the FSU Superensemble prediction. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 21.2N 56.4W 40 KT 45 MPH 12H 25/1800Z 21.7N 57.0W 45 KT 50 MPH 24H 26/0600Z 22.1N 57.6W 50 KT 60 MPH 36H 26/1800Z 22.6N 58.4W 55 KT 65 MPH 48H 27/0600Z 23.0N 59.4W 60 KT 70 MPH 60H 27/1800Z 23.5N 61.0W 75 KT 85 MPH 72H 28/0600Z 24.3N 63.0W 90 KT 105 MPH 96H 29/0600Z 26.7N 66.8W 100 KT 115 MPH 120H 30/0600Z 30.6N 69.3W 95 KT 110 MPH $$ Forecaster Bucci
