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| #1062324 (Received by flhurricane at: 5:06 AM 19.Sep.2021) TCDAT2 Tropical Depression Seventeen Discussion Number 1 NWS National Hurricane Center Miami FL AL172021 800 AM CVT Sun Sep 19 2021 The small low pressure system that the NHC has been tracking the past few days has acquired a well-defined circulation and enough organized deep convection to be classified as a tropical depression. The initial intensity of 30 kt is based on 0000 UTC ASCAT wind data of about 30 kt. This intensity is also supported by consensus Dvorak satellite classifications of T2.0/30 kt from TAFB and SAB. The initial motion estimate is north-northwestward or 330/12 kt. The small 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. The NHC forecast track lies down the middle of the tightly packed track models. Only modest strengthening is expected during the next 48 hour so while the small cyclone remains over 27-28 deg C sea-surface temperatures and the vertical wind shear decreases to near 5 kt during that time. However, proximity to dry air is expected prevent any significant strengthening from occurring. By late Tuesday, a slow weakening trend is forecast to begin as the system moves over cooler water and the shear increases from the southwest. The NHC intensity forecast closely follows a blend of the IVCN and HCCA intensity consensus models through 72 hours, and then is lower than the HCCA model on days 4 and 5. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 11.8N 28.2W 30 KT 35 MPH 12H 19/1800Z 13.4N 29.2W 35 KT 40 MPH 24H 20/0600Z 15.5N 31.2W 40 KT 45 MPH 36H 20/1800Z 17.6N 33.2W 40 KT 45 MPH 48H 21/0600Z 19.7N 34.7W 35 KT 40 MPH 60H 21/1800Z 21.7N 36.1W 35 KT 40 MPH 72H 22/0600Z 23.2N 37.2W 30 KT 35 MPH 96H 23/0600Z 25.6N 39.6W 30 KT 35 MPH 120H 24/0600Z 28.1N 41.5W 30 KT 35 MPH $$ Forecaster Stewart |