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#1062364 (Received by flhurricane at: 11:06 AM 19.Sep.2021) TCDAT2 Tropical Depression Seventeen Discussion Number 2 NWS National Hurricane Center Miami FL AL172021 200 PM CVT Sun Sep 19 2021 The low-level center of the depression was exposed on visible satellite imagery this morning but recently a new burst has formed. Since the morning scatterometer passes missed the depression, the intensity is held at 30 kt based on consensus T-2.0 values from TAFB and SAB. The initial motion estimate is 330/12. The cyclone is forecast to move in a general northwestward direction throughout the remainder of the forecast period as the system moves along the southwestern and western periphery of a subtropical ridge that extends westward from Africa across the Cabo Verde Islands. No significant changes were made to the previous NHC forecast track, and the new prediction lies near the middle of the tightly clustered track models. Environmental conditions are conducive for strengthening during the next day or so, with wind shear forecast to drop off later today. Thus, the official forecast calls for strengthening during the next 24 hours, and is close to the lower half of the intensity guidance envelope, near the weaker global models. This forecast could be conservative, since SSTs will be near 27C and mid-level atmospheric moisture will be enough to support intensification. By 36-48 hours, the southwesterly shear will increase, which should end the opportunity for strengthening, and will likely cause slow weakening. The models hold onto this system through the 5 day period, but it is possible that the cyclone could become a remnant low in 4-5 days if the shear is too much for the system to handle. FORECAST POSITIONS AND MAX WINDS INIT 19/1500Z 13.2N 28.8W 30 KT 35 MPH 12H 20/0000Z 14.7N 30.1W 35 KT 40 MPH 24H 20/1200Z 16.7N 32.2W 40 KT 45 MPH 36H 21/0000Z 18.9N 33.9W 40 KT 45 MPH 48H 21/1200Z 21.0N 35.4W 35 KT 40 MPH 60H 22/0000Z 22.7N 36.5W 35 KT 40 MPH 72H 22/1200Z 24.0N 37.6W 35 KT 40 MPH 96H 23/1200Z 26.3N 39.9W 30 KT 35 MPH 120H 24/1200Z 28.3N 41.2W 30 KT 35 MPH $$ Forecaster Hagen/Blake |