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| #1056807 (Received by flhurricane at: 5:51 AM 14.Aug.2021) TCDAT1 Tropical Depression Fred Discussion Number 19 NWS National Hurricane Center Miami FL AL062021 500 AM EDT Sat Aug 14 2021 The interaction with the landmass of Cuba has significantly disrupted the circulation of Fred. In fact, radar data from Cuba, satellite images, earlier ASCAT data, and surface observations suggest that the system is likely an open trough with the strongest winds and deep convection occurring to the south of central Cuba. Fred is being maintained as a tropical depression for now, but data from the Air Force Hurricane Hunters later this morning will likely confirm if it is a depression or not. The initial intensity is held at 30 kt based on the aforementioned ASCAT data. Bands of heavy rain are now spreading across the Florida Keys. The initial motion of 295/11 kt is highly uncertain since its not clear if Fred has a center. Even though the storm has moved farther west than previously expected, the overall track forecast reasoning has not changed much. Fred is expected to turn northwestward by tonight and northward by Sunday night as the cyclone rounds the western periphery of a subtropical ridge. The new track forecast has been nudged to the west again to be in better agreement with the latest model consensus aids. Based on the new track forecast, Fred is expected to pass west of the lower Florida Keys later today and make landfall along the western Florida Panhandle or Alabama coast Monday night or early Tuesday. Although Fred is very disorganized at the moment, the global models show the circulation becoming better defined tonight or on Sunday as the cyclone moves over the eastern Gulf of Mexico in slightly lower wind shear conditions. The storm is expected to strengthen some during the next couple of days, but significant intensification seems unlikely as southerly shear is anticipated to increase before the system reaches the Gulf coast on Monday. GFS and ECMWF simulated satellite images show an asymmetric cyclone with most of the associated convection and stronger winds on its east side while Fred moves across the Gulf of Mexico. After landfall, steady weakening is expected, and Fred is likely to dissipate by the middle of next week. The NHC intensity forecast is largely an update of the previous one and lies near the high end of the model guidance. KEY MESSAGES: 1. Today through Monday, heavy rainfall could lead to areal, urban, and small stream flooding impacts, and cause new and renewed river flooding, across southern Florida, the Big Bend, and Panhandle. From Monday onward, heavy rain and flood impacts could extend into other portions of the Southeast and into the southern and central Appalachians and Piedmont as Fred interacts with a front in the area. 2. Tropical storm conditions are expected in portions of the Lower Florida Keys later today, where a Tropical Storm Warning is in effect. 3. There is a risk of tropical storm conditions in the Florida Panhandle and coastal Alabama beginning on Monday. Watches may be required for a portion of this area later today. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 23.3N 81.7W 30 KT 35 MPH 12H 14/1800Z 24.0N 83.1W 30 KT 35 MPH 24H 15/0600Z 25.4N 84.6W 35 KT 40 MPH 36H 15/1800Z 27.0N 85.8W 40 KT 45 MPH 48H 16/0600Z 28.4N 86.7W 45 KT 50 MPH 60H 16/1800Z 29.8N 87.3W 50 KT 60 MPH 72H 17/0600Z 30.9N 87.4W 40 KT 45 MPH...INLAND 96H 18/0600Z 34.4N 86.6W 25 KT 30 MPH...INLAND 120H 19/0600Z...DISSIPATED $$ Forecaster Cangialosi |