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| #1108052 (Received by flhurricane at: 10:48 AM 20.Sep.2022) TCDAT3 Tropical Depression Eight Discussion Number 1 NWS National Hurricane Center Miami FL AL082022 Issued by the NWS Weather Prediction Center College Park MD 1100 AM AST Tue Sep 20 2022 Geostationary and microwave satellite data indicate that the system that NHC has been monitoring over the central Atlantic has developed a well-defined center and organized deep convection, and now meets the definition of a tropical cyclone. The initial intensity is estimated to be 30 kt based on a partial ASCAT pass that showed peak winds in the 25-30 kt range. The low-level center is estimated to be on the southern side of the main area of deep convection. The depression is currently moving northward at 9 kt on the western side of a subtropical ridge. A faster motion to the northeast is expected on Wednesday when the system reaches the northwestern periphery of the ridge, followed by a turn to the east. By the end of the week, however, the depression is expected to stall in weak steering currents as high pressure builds near and to the north of the cyclone. Over the weekend, the depression is expected to turn northwestward and increase its forward speed as Fiona tracks well to the west of this system. The models are in fair agreement, but there is some cross-track spread by the end of the period with the GFS showing the fastest solution and ECMWF the slowest. The NHC track forecast lies close to the various consensus models. The depression is currently over relatively warm water, in a region of upper-level diffluence within a somewhat favorable moist environment. These factors should allow the system to strengthen slowly during the next couple of days. However, after that time, much cooler SSTs, drier air, and an increase in westerly shear should end the strengthening trend. The system is expected to become extratropical over the weekend when it moves over SSTs just above 20C. The NHC intensity forecast lies a little lower than HCCA and IVCN consensus models. Interests in the Azores should monitor forecasts of the depression. FORECAST POSITIONS AND MAX WINDS INIT 20/1500Z 32.8N 45.7W 30 KT 35 MPH 12H 21/0000Z 34.6N 45.0W 35 KT 40 MPH 24H 21/1200Z 36.7N 43.2W 40 KT 45 MPH 36H 22/0000Z 38.2N 40.6W 45 KT 50 MPH 48H 22/1200Z 39.2N 37.8W 50 KT 60 MPH 60H 23/0000Z 39.7N 35.3W 50 KT 60 MPH 72H 23/1200Z 39.8N 33.7W 50 KT 60 MPH 96H 24/1200Z 40.1N 33.7W 50 KT 60 MPH 120H 25/1200Z 42.4N 36.9W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi/Pereira/Montgomery |
