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#982630 (Received by flhurricane at: 10:57 AM 17.Sep.2019) TCDAT5 Tropical Depression Ten Discussion Number 1 NWS National Hurricane Center Miami FL AL102019 1100 AM AST Tue Sep 17 2019 Deep convection associated with the area of low pressure over the central Atlantic has become more persistent and better organized this morning. Data T-numbers from both SAB and TAFB are 2.0 on the Dvorak scale, therefore advisories are being initiated on a tropical depression. The initial intensity is set at 30 kt, in line with the satellite estimates. The depression is forecast to move over gradually increasing sea surface temperatures within a favorable upper-level environment. The only negative factor for intensification appears to be some nearby dry air, but with low shear conditions expected, so steady strengthening is forecast during the next several days. The NHC forecast calls for the depression to become a tropical storm later today, and attain hurricane status within 72 hours. The NHC intensity forecast is in good agreement with the SHIPS and LGEM statistical models. Since the depression is still in the development phase, the initial motion is a somewhat uncertain 295/10 kt. A strong deep-layer ridge to the north of the cyclone should steer the depression generally west-northwestward at a faster forward speed during the next few days. The track guidance is in relatively good agreement through 72 hours, and brings the cyclone near the northern Leeward Islands in about 3 days. By late in the period, the cyclone is expected to reach the western periphery of the ridge, and there is increasing spread among the guidance. The global model ensemble means are along the right side of the envelope while the HWRF and UKMET are along the left side. The NHC track lies close the consensus aids, which is also in good agreement with the latest ECMWF. Interests in the northern Leeward Islands should monitor the progress of this system. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 12.9N 44.9W 30 KT 35 MPH 12H 18/0000Z 13.8N 46.1W 35 KT 40 MPH 24H 18/1200Z 14.7N 47.9W 40 KT 45 MPH 36H 19/0000Z 15.5N 50.2W 45 KT 50 MPH 48H 19/1200Z 16.3N 52.9W 55 KT 65 MPH 72H 20/1200Z 18.2N 59.2W 65 KT 75 MPH 96H 21/1200Z 20.2N 64.7W 75 KT 85 MPH 120H 22/1200Z 22.5N 69.0W 80 KT 90 MPH $$ Forecaster Brown |