Issued at 500 PM AST Thu Sep 25 2025
019 WTNT43 KNHC 252037 TCDAT3 Tropical Storm Humberto Discussion Number 5 NWS National Hurricane Center Miami FL AL082025 500 PM AST Thu Sep 25 2025 Humberto continues to gradually gain strength over the central Atlantic. Deep convection has been increasing over the center, and the cloud pattern is more symmetric than it was earlier today. This is an indication that the wind shear around the storm is lessening. Recent microwave images indicate that an inner core appears to be forming, and an earlier ASCAT pass showed maximum winds of about 45 kt. Based on the improving satellite presentation, the initial intensity is increased to 50 kt. This value is also near the average of the latest satellite intensity estimates. The 34-kt wind radii have been adjusted based on the ASCAT data. Steady to rapid strengthening is expected during the next few days as the storm moves into a more favorable environment of light winds aloft and high moisture. Given that Humberto is relatively compact and an increasingly symmetric system, these conditions should cause it to become a hurricane on Friday and a major hurricane over the weekend. Less favorable environmental conditions should cause some weakening early next week. This prediction remains in line with the latest HCCA and IVCN consensus models. The storm has jogged a little to the north today, but the overall motion is northwestward at 5 kt. Humberto remains embedded in weak steering currents on the south side of a narrow and weak subtropical high over the central Atlantic. This pattern should keep the storm moving slowly to the west-northwest or northwest during the next day or two. After that time, Humberto is expected to become increasingly steered by a much stronger high over the western Atlantic, which should cause the storm to accelerate. The NHC track forecast is a little slower than the previous one, trending toward the latest consensus and Google Deep Mind models. This forecast keeps Humberto over the open central and western subtropical Atlantic during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 25/2100Z 21.9N 57.0W 50 KT 60 MPH 12H 26/0600Z 22.3N 57.4W 60 KT 70 MPH 24H 26/1800Z 22.5N 58.0W 70 KT 80 MPH 36H 27/0600Z 22.7N 59.1W 80 KT 90 MPH 48H 27/1800Z 23.0N 60.8W 90 KT 105 MPH 60H 28/0600Z 23.6N 62.7W 100 KT 115 MPH 72H 28/1800Z 24.6N 64.7W 105 KT 120 MPH 96H 29/1800Z 28.0N 68.2W 105 KT 120 MPH 120H 30/1800Z 31.6N 69.9W 90 KT 105 MPH $$ Forecaster Cangialosi
