Issued at 500 AM AST Wed Sep 17 2025
000 WTNT42 KNHC 170835 TCDAT2 Tropical Depression Seven Discussion Number 1 NWS National Hurricane Center Miami FL AL072025 500 AM AST Wed Sep 17 2025 Satellite data indicate that Invest 92L over the central tropical Atlantic has now developed into a tropical depression. ASCAT data from around 00Z showed that the circulation of the system had improved, and although it was not well defined at the time of the pass, the system was only lacking some northerly winds on its west side. Since deep convection has been persisting and consolidating near the center, it appears to now meet the convective and circulation criteria needed to be considered a tropical cyclone. However, it should be noted that the system is quite large and there is still considerable north-south elongation in the low-level structure. The initial intensity is set at 30 kt based on a blend of the ASCAT data and the latest Dvorak estimate from TAFB. The development of this system breaks a nearly 3-week streak of no tropical cyclones in the Atlantic basin during the peak of the hurricane season. The depression is well away from land and roughly midway between the Cabo Verde Islands and the Windward Islands. The system is estimated to be moving westward at 11 kt, but this is of low confidence since the center has only recently formed. A turn to the northwest, perhaps influenced by a center formation, is expected to occur soon as the depression moves toward a weakness in the Atlantic subtropical ridge caused by a mid- to upper-level low to its north. The models show this low weakening in a day or two, which will likely cause the cyclone to turn back to the west-northwest late this week. However, the system should reach the western periphery of the ridge this weekend, resulting in a turn to the northwest or north. The NHC track forecast is a little to the right of the consensus aids, giving more weight to the ECMWF and Google Deep Mind predictions, which are faster and on the right side of the guidance. Based on the steering pattern, and deterministic and ensemble model solutions, there is high confidence that this system should pass well east of the Windward and Leeward Islands. Interests in Bermuda should monitor forecasts of the depression over the next several days. Only modest strengthening is expected over the next day or two as the depression continues to battle moderate shear from the aforementioned low aloft and intrusions of dry air. However, more notable strengthening seems likely by the weekend when the system moves into more conducive environmental conditions. The NHC intensity forecast shows the system reaching hurricane strength toward the end of the period, but it should be noted that the spread in the models at that time is significant and ranges from solutions showing a weak low to a major hurricane. This prediction is generally in line with the IVCN aid. FORECAST POSITIONS AND MAX WINDS INIT 17/0900Z 13.7N 45.9W 30 KT 35 MPH 12H 17/1800Z 15.8N 47.4W 35 KT 40 MPH 24H 18/0600Z 17.6N 49.6W 40 KT 45 MPH 36H 18/1800Z 19.0N 51.9W 40 KT 45 MPH 48H 19/0600Z 19.7N 54.0W 45 KT 50 MPH 60H 19/1800Z 20.4N 55.9W 50 KT 60 MPH 72H 20/0600Z 21.6N 57.6W 55 KT 65 MPH 96H 21/0600Z 24.0N 60.0W 65 KT 75 MPH 120H 22/0600Z 26.9N 63.0W 75 KT 85 MPH $$ Forecaster Cangialosi
NHC Atlantic
