Official Discussion issued by the National Hurricane Center
Debby (AL042024) DATA RELEASED: 8/5/2024 9:00:00 AM UTC
Copy of official data Hurricane Debby Discussion Number 12 NWS National Hurricane Center Miami FL AL042024 500 AM EDT Mon Aug 05 2024 The eyewall of Debby is moving onshore and landfall in the Florida Big Bend is expected to occur within the next few hours. Doppler radar images from Tallahassee indicate that the eye of the hurricane has become a bit more circular and deep convection remains fairly well organized over the eastern eyewall, and in bands east of the center that have spread across portions of northern Florida. There have been numerous reports of sustained tropical-storm-force winds, but the strongest so far is in Horseshoe Beach, where a weather station recently recorded a sustained wind of 57 kt and a gust to 83 kt. Data from the Air Force Hurricane Hunters indicate that the maximum winds are likely near 70 kt, and Debby will likely maintain that intensity or strengthen a little until it reaches the coast. After landfall, Debby is expected to slow down and turn northeastward as the steering currents collapse, taking the system across northern Florida and southeastern Georgia later today through Tuesday. Most of the models show Debby moving off the southeast U.S. coast late Tuesday and Wednesday before a ridge builds to the north of the system, which should push it back inland over South Carolina on Thursday. Although the details of the track forecast are unknown, there is high confidence that Debby will move slowly while near or over the southeastern U.S., which will likely result in catastrophic flooding in some locations. The NHC track forecast is similar to the previous one and in line with the consensus aids. Rapid weakening is forecast after the center moves inland, and Debby will likely become a tropical storm over northern Florida this afternoon. If Debby does move back offshore of the southeast U.S., there could be a little strengthening before it moves inland once again. Regardless of the system's strength, the main impact is expected to be heavy rainfall as mentioned above. The NHC intensity forecast is generally similar to the previous one and near the HCCA and IVCN aids. NHC has begun issuing hourly Tropical Cyclone Updates, and they will continue through landfall. Key Messages: 1. Potentially historic heavy rainfall across southeast Georgia and the coastal plain of South Carolina through Saturday morning will likely result in areas of catastrophic flooding. Heavy rainfall will likely result in considerable flooding impacts from portions of central and northern Florida and across portions of central and northeast North Carolina through Saturday morning. 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 to Yankeetown through the morning. Residents in the Storm Surge Warning area should follow any advice given by local officials. 3. Hurricane conditions are expected this morning along portions of the Florida Big Bend region where a Hurricane Warning is in effect. Tropical storm conditions are expected to continue for several more hours farther south within the Tropical Storm Warning area 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 are in effect for portions of these areas. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 29.5N 83.7W 70 KT 80 MPH 12H 05/1800Z 30.5N 83.1W 55 KT 65 MPH...INLAND 24H 06/0600Z 31.3N 82.1W 45 KT 50 MPH...INLAND 36H 06/1800Z 31.8N 81.1W 45 KT 50 MPH...INLAND 48H 07/0600Z 31.9N 80.2W 45 KT 50 MPH...OVER WATER 60H 07/1800Z 32.1N 79.6W 45 KT 50 MPH...OVER WATER 72H 08/0600Z 32.3N 79.6W 50 KT 60 MPH...OVER WATER 96H 09/0600Z 33.5N 79.6W 40 KT 45 MPH...INLAND 120H 10/0600Z 35.6N 78.9W 30 KT 35 MPH...INLAND $$ Forecaster Cangialosi |