Issued at 1100 PM AST Sat Sep 20 2025
000 WTNT42 KNHC 210237 TCDAT2 Tropical Storm Gabrielle Discussion Number 16 NWS National Hurricane Center Miami FL AL072025 1100 PM AST Sat Sep 20 2025 Recent GMI and SSMIS passive microwave images of Gabrielle suggest the tight inner core noted in earlier aircraft data has collapsed. A larger mid-level eye structure now wraps over halfway around the circulation but is open to the southwest. The low-level center of the storm lies near the sharp western edge of the convective cloud mass, which suggests Gabrielle is still contending with some shear. Convective band wraps around the eastern side of the storm, where recent ASCAT-B data confirm the strongest surface winds are occurring. The initial intensity is set at 55 kt based on TAFB Dvorak and UW-CIMSS objective satellite intensity estimates. Air Force Reserve Hurricane Hunters are scheduled to investigate the storm tomorrow morning. Gabrielle is moving north-northwestward (335/8 kt) along the southwestern side of a subtropical ridge over the central Atlantic. Over the next couple of days, Gabrielle is expected to recurve to the north and northeast between this ridge and a mid-latitude trough over the eastern United States. The track models remain in good near-term agreement, and the updated NHC track forecast keeps Gabrielle well east of Bermuda on Monday. Then, Gabrielle is forecast to accelerate east-northeastward through the rest of the week while embedded in zonal westerly flow. There are greater speed differences in the track models during the latter half of the forecast period, but the consensus has trended slower once again, and this is reflected in the updated NHC forecast. Assuming Gabrielle is able to solidify its inner core soon, some strengthening is expected over warm waters within a low to moderate shear environment during the next couple of days. The latest track guidance is not quite as aggressive as earlier today. The NHC forecast is very similar to the previous one, remaining close to the HFIP corrected consensus (HCCA) near the higher end of the guidance envelope. By Tuesday, increased westerly shear is forecast to cause Gabrielle to weaken, especially while it moves over cooler waters later next week. The long-range forecast track uncertainty makes it difficult to assess whether Gabrielle will fully complete extratropical transition by the end of the period. However, it seems likely that the system will be losing tropical characteristics and in close proximity to fronts by Friday. KEY MESSAGES: 1. Gabrielle is forecast to become a hurricane on Sunday and pass east of Bermuda on Monday. While the chances of impacts are decreasing, interests on Bermuda should continue to monitor forecast updates since some wind and rainfall impacts are still possible. 2. Swells generated by Gabrielle will continue to affect Bermuda through early next week. These swells are expected to reach the coast of the United States from North Carolina northward, along with the coast of Atlantic Canada, on Sunday and continue through early next week. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 21/0300Z 26.3N 59.2W 55 KT 65 MPH 12H 21/1200Z 27.4N 60.3W 65 KT 75 MPH 24H 22/0000Z 29.1N 61.3W 75 KT 85 MPH 36H 22/1200Z 30.7N 61.5W 85 KT 100 MPH 48H 23/0000Z 32.3N 60.5W 90 KT 105 MPH 60H 23/1200Z 33.8N 58.2W 85 KT 100 MPH 72H 24/0000Z 35.1N 54.5W 80 KT 90 MPH 96H 25/0000Z 36.5N 44.0W 65 KT 75 MPH 120H 26/0000Z 39.0N 31.5W 60 KT 70 MPH $$ Forecaster Reinhart
NHC Atlantic
