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#873373 (Received by flhurricane at: 10:50 AM 30.Aug.2016) TCDAT4 TROPICAL DEPRESSION NINE DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092016 1000 AM CDT TUE AUG 30 2016 Deep convection once again increased in association with the cyclone this morning, and satellite images show that very heavy rains continue over portions of western Cuba, where significant flooding is likely occurring. However, the overall organization of the system has not changed much since last night. Dvorak T-numbers from TAFB and SAB have not increased, so the intensity is kept at 30 kt for this advisory. Another NOAA Hurricane Hunter Aircraft is scheduled to investigate the cyclone this afternoon to see if the depression has become a tropical storm. The dynamical guidance indicates that the vertical shear over the system will decrease slightly during the next day or so but, starting around 48 hours, westerly shear is forecast to begin increasing. This should limit strengthening while the system approaches northern Florida. The official intensity forecast was lowered slightly around 48 hours, in agreement with the latest intensity model consensus. At the moment, there is no intensity guidance that makes this system a hurricane prior to landfall. Visible and microwave imagery, in particular a 1222 UTC SSMIS overpass, suggest that the center is located near the northern edge of the dense overcast, and the motion is estimated to be west-northwestward or 290/6 kt. There is little change to the track forecast philosophy. A mid-tropospheric trough that is expected to develop over the southeastern United States should induce a turn toward the north, and then northeast, with a gradual increase in forward speed over the next few days. This would bring the center of the cyclone across the northern Florida peninsula within 60-72 hours. The official track forecast is about the same as the previous one, and is mainly a blend of the GFS and ECMWF predictions. Given the current forecast, a tropical storm watch may be required for a portion of the Florida Gulf coast later today. FORECAST POSITIONS AND MAX WINDS INIT 30/1500Z 24.0N 87.2W 30 KT 35 MPH 12H 31/0000Z 24.5N 87.3W 35 KT 40 MPH 24H 31/1200Z 25.4N 87.4W 40 KT 45 MPH 36H 01/0000Z 26.9N 86.2W 45 KT 50 MPH 48H 01/1200Z 28.5N 84.5W 50 KT 60 MPH 72H 02/1200Z 31.6N 79.0W 50 KT 60 MPH 96H 03/1200Z 34.0N 72.0W 50 KT 60 MPH 120H 04/1200Z 36.5N 66.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch |