Issued at 500 AM AST Sat Sep 27 2025
000 WTNT43 KNHC 270845 TCDAT3 Hurricane Humberto Discussion Number 11 NWS National Hurricane Center Miami FL AL082025 500 AM AST Sat Sep 27 2025 Humberto seems to have paused its meteoric rise for the moment. The eye has become smaller and more distorted based on GOES satellite imagery. An AMSR2 microwave pass showed some evidence that the concentric rings mentioned in the previous discussion have contracted, indicating an ongoing eyewall replacement cycle. The microwave images also displayed classic hurricane structure, with curved banding in all quadrants and no signs of dry air intrusions. The satellite intensity estimates have leveled off overnight, and the initial intensity is held at 125 kt, closest to the UW-CIMSS ADT of T6.3. While internal dynamics may have interrupted Humberto's strengthening, the hurricane still has about a day of conducive environmental and oceanic conditions to intensify. Some of the regional hurricane models show slight strengthening, though most of the model guidance suggests Humberto will hold generally steady for the next couple of days. By next week, the vertical wind shear is expected to increase and induce a gradual weakening trend. As Humberto gains latitude, a significant expansion in the surface wind field will likely occur while it passes west of Bermuda. Phase-space analyses of global model forecasts by day 5 show Humberto as an extratropical cyclone, or close to one. The latest NHC intensity forecast is very similar to the previous prediction and lies on the high end of the guidance in the short-term. The hurricane is moving westward at 5 kt. A subtropical ridge centered over the western Atlantic should slowly steer Humberto to the west or west-northwest during the next day or so, then turn the cyclone to the northwest and north-northwest by early next week. By day 4, an amplifying upper-level trough moving out of the Canadian Maritimes is expected to rapidly steer Humberto northeastward. The NHC track forecast shifted slightly eastward this cycle and is a little quicker at days 4 and 5. It lies between the Google DeepMind ensemble mean and the previous prediction. FORECAST POSITIONS AND MAX WINDS INIT 27/0900Z 22.3N 59.3W 125 KT 145 MPH 12H 27/1800Z 22.6N 60.5W 135 KT 155 MPH 24H 28/0600Z 23.3N 62.3W 140 KT 160 MPH 36H 28/1800Z 24.4N 64.3W 135 KT 155 MPH 48H 29/0600Z 25.8N 66.0W 130 KT 150 MPH 60H 29/1800Z 27.3N 67.3W 125 KT 145 MPH 72H 30/0600Z 29.1N 68.1W 115 KT 130 MPH 96H 01/0600Z 33.4N 66.5W 100 KT 115 MPH 120H 02/0600Z 37.7N 56.4W 90 KT 105 MPH...POST-TROP/EXTRATROP $$ Forecaster Bucci
NHC Atlantic
