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#803198 (Received by flhurricane at: 4:34 PM 16.Sep.2015) TCDAT4 TROPICAL DEPRESSION NINE DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092015 500 PM AST WED SEP 16 2015 The satellite presentation of the depression has degraded during the past few hours, with dry air and southwesterly shear resulting in the convection become displaced from the low-level center. The convection itself has not become better organized, and has a rather linear shape to the east and northeast of the center. The initial intensity remains 25 kt based on the latest Dvorak estimate from SAB. The prospects for the cyclone to strengthen, or even survive, appear quite poor. The shear is forecast to increase markedly in the next 12 to 24 hours, and the shear in combination with dry air should result in the cyclone weakening to a remnant low by 48 hours. The NHC forecast continues to show dissipation by 5 days, in best agreement with the latest GFS forecast. The exposed low-level center is located about a degree to the west of the previous advisory estimate, with an initial motion of 310/07. The initial position and motion have resulted in a leftward adjustment to the track forecast this cycle of 1 to 2 degrees. The new NHC forecast lies between the shallow BAM and to the left of the rest of the model guidance in the short term given the sheared nature of the system and its current motion. After that time, the NHC forecast is close to the HWRF and GEFS ensemble mean and still left of the multi-model consensus aids. Given the current disorganized state of the depression, the track forecast is quite uncertain through the period. FORECAST POSITIONS AND MAX WINDS INIT 16/2100Z 15.2N 44.6W 25 KT 30 MPH 12H 17/0600Z 15.9N 45.1W 25 KT 30 MPH 24H 17/1800Z 17.0N 45.8W 30 KT 35 MPH 36H 18/0600Z 18.0N 46.4W 25 KT 30 MPH 48H 18/1800Z 19.3N 47.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 19/1800Z 20.5N 49.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 20/1800Z 21.5N 52.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 21/1800Z...DISSIPATED $$ Forecaster Brennan |