Issued at 1100 PM AST Thu Sep 25 2025
000 WTNT43 KNHC 260241 TCDAT3 Tropical Storm Humberto Discussion Number 6 NWS National Hurricane Center Miami FL AL082025 1100 PM AST Thu Sep 25 2025 Humberto continues to gain strength while moving slowly over the central Atlantic. The system is exhibiting a growing CDO feature with cloud tops to near -70 deg C, along with some convective bands over the eastern portion of the circulation, where most of the lightning flashes are currently occurring. The advisory intensity is increased to 55 kt, in agreement with subjective Dvorak classifications from both TAFB and SAB and a blend of objective satellite estimates from UW-CIMSS. The storm's forward speed is quite slow with a motion estimate of only 320/3 kt. Steering currents are not strong at this time since the subtropical ridge to the north of Humberto is quite weak. Global model forecasts show the ridge strengthening with time and in a few days the cyclone should move somewhat faster toward the northwest and turn northward in the vicinity of 70 W longitude. By the end of the forecast period, after Humberto passes north of the ridge, the system should begin accelerating northeastward. Cirrus motions indicate that the vertical wind shear over Humberto has lessened, and the SHIPS model output does not show the shear increasing much through 72 hours. Sea surface temperatures are expected to be very warm along the projected path of the cyclone, and the system should remain embedded in a moist air mass. The official forecast continues to call for significant strengthening during the next few days. This is consistent with the latest corrected consensus, HCCA, forecast which also shows Humberto intensifying into a major hurricane this weekend. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 22.2N 57.1W 55 KT 65 MPH 12H 26/1200Z 22.4N 57.6W 65 KT 75 MPH 24H 27/0000Z 22.7N 58.5W 75 KT 85 MPH 36H 27/1200Z 22.9N 59.9W 90 KT 105 MPH 48H 28/0000Z 23.4N 61.8W 105 KT 120 MPH 60H 28/1200Z 24.3N 63.8W 110 KT 125 MPH 72H 29/0000Z 25.4N 65.7W 110 KT 125 MPH 96H 30/0000Z 29.0N 69.0W 100 KT 115 MPH 120H 01/0000Z 32.6N 69.7W 90 KT 105 MPH $$ Forecaster Pasch
