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| #1192019 (Received by flhurricane at: 4:57 PM 04.Aug.2024) TCDAT4 Tropical Storm Debby Discussion Number 10 NWS National Hurricane Center Miami FL AL042024 500 PM EDT Sun Aug 04 2024 Debby's cloud pattern continues to show increasing organization on satellite images although there is limited deep convection over the southwest quadrant of the circulation. The upper-level anticyclonic outflow pattern is well-defined. The latest Air Force Hurricane Hunter aircraft observations indicated that the central pressure hadn't changed much and the wind data from the aircraft continued to support an intensity of near 55 kt. WSR-88D radar imagery shows that an eyewall may be trying to close off, and another Hurricane Hunter aircraft will be investigating Debby in a few hours to assess the strength of the cyclone. The cyclone has turned toward the north and is now moving at around 360/10 kt. Debby should continue to move through a break in the subtropical ridge due to a trough over the eastern United States for the next day or so, and this motion should bring the center of the system to the northeast Gulf of Mexico coast around midday tomorrow. Thereafter, the trough moves eastward, leaving Debby in weak steering currents for a few days. The track guidance shows decreasing forward speed and a turn to the east in 24-48 hours. Some of the track models show the cyclone moving temporarily over the Atlantic in the 72-hour time frame, and so does the official forecast. Debby will continue to move over waters of high heat content and remain in an environment of low vertical wind shear into Monday morning. Some dry air intrusion over the southwestern portion of the circulation may have temporarily interrupted the intensification process. However, given the favorable oceanic and shear conditions, significant strengthening is expected before landfall. Rapid intensification is especially likely if Debby acquires a well-defined inner core. The official intensity forecast is at the high end of the model guidance. Although weakening will occur after landfall, the longer-term strength of the system is largely dependent on how long it remains over land. Currently the official forecast shows some re-intensification with Debby moving into the Atlantic, but how much the system will restrengthen is highly uncertain. Key Messages: 1. Potentially historic heavy rainfall across southeast Georgia and South Carolina through Friday morning will likely result in areas of catastrophic flooding. Heavy rainfall will likely result in considerable flooding impacts from the Florida Big Bend region through southeast GA and the Coastal Plain of the Carolinas through Friday. 2. There is a danger of life-threatening storm surge along portions of the Gulf Coast of Florida, with 6 to 10 feet of inundation above ground level expected somewhere between Ochlockonee River and Suwannee River on Monday. Residents in the Storm Surge Warning area should follow any advice given by local officials. 3. Hurricane conditions are expected Monday along portions of the Florida Big Bend region where a Hurricane Warning is in effect, with tropical storm conditions beginning this evening. Tropical storm conditions are expected through Monday farther south within the Tropical Storm Warning along Florida's west coast, including the Tampa Bay area. 4. Dangerous storm surge and wind impacts are expected along portions of the southeast U.S. coast from northeastern Florida to North Carolina through the middle of the week, and storm surge warnings and tropical storm watches and warnings have been issued for portions of these areas. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 27.7N 84.4W 55 KT 65 MPH 12H 05/0600Z 29.1N 84.4W 75 KT 85 MPH 24H 05/1800Z 30.5N 83.8W 75 KT 85 MPH...INLAND 36H 06/0600Z 31.3N 83.0W 45 KT 50 MPH...INLAND 48H 06/1800Z 31.7N 82.1W 35 KT 40 MPH...INLAND 60H 07/0600Z 31.7N 81.1W 40 KT 45 MPH...INLAND 72H 07/1800Z 31.9N 80.5W 45 KT 50 MPH...OVER WATER 96H 08/1800Z 32.6N 80.1W 45 KT 50 MPH...INLAND 120H 09/1800Z 34.0N 79.5W 30 KT 35 MPH...INLAND $$ Forecaster Pasch |
