Issued at 800 PM EDT Sun Aug 04 2024
858 WTNT34 KNHC 042353 TCPAT4 BULLETIN Tropical Storm Debby Intermediate Advisory Number 10A NWS National Hurricane Center Miami FL AL042024 800 PM EDT Sun Aug 04 2024 ...DEBBY STRENGTHENING AS IT HEADS TOWARD THE FLORIDA BIG BEND AREA... ...WILL BRING A MAJOR FLOOD THREAT TO THE SOUTHEASTERN UNITED STATES THIS WEEK... SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...28.1N 84.1W ABOUT 100 MI...160 KM W OF TAMPA FLORIDA ABOUT 90 MI...150 KM SW OF CEDAR KEY FLORIDA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Florida coast from the middle of Longboat Key northward to Indian Pass including Tampa Bay * Georgia and South Carolina coast from the Mouth of the St. Mary's River to South Santee River South Carolina A Storm Surge Watch is in effect for... * Florida coast from Bonita Beach northward to the middle of Longboat Key, including Charlotte Harbor A Hurricane Warning is in effect for... * Florida coast from the Suwannee River to Indian Pass A Hurricane Watch is in effect for... * Florida coast south of the Suwannee River to Yankeetown A Tropical Storm Warning is in effect for... * Florida coast south of the Suwannee River to Bonita Beach * Florida coast from west of Indian Pass to Mexico Beach * Ponte Vedre Beach to the Savannah River A Tropical Storm Watch is in effect for... * Savannah River to South Santee River South Carolina A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. Interests elsewhere along the southeastern coast of the United States should monitor the progress of this system. Additional watches and warnings will likely be required tonight or Monday. For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 800 PM EDT (0000 UTC), the center of Tropical Storm Debby was located near latitude 28.1 North, longitude 84.1 West. Debby is moving toward the north near 12 mph (19 km/h). A gradual decrease in forward speed with a turn toward the northeast and east is expected on Monday and Tuesday. On the forecast track, the center will move across the northeastern Gulf of Mexico through tonight and reach the Florida Big Bend coast around midday Monday. Debby is then expected to move slowly across northern Florida and southern Georgia Monday and Tuesday. Maximum sustained winds have increased to near 70 mph (110 km/h) with higher gusts. Rapid strengthening is forecast, and Debby is expected to become a hurricane tonight, with additional strengthening likely before it reaches the Florida Big Bend coast on Monday. Weakening is expected on Monday and Tuesday after Debby moves inland. Tropical-storm-force winds extend outward up to 140 miles (220 km) from the center. NOAA Buoy 42036 recently reported sustained winds of 45 mph (72 km/h) with a gust to 56 mph (90 km/h). A wind gust to 60 mph (96 km/h) has been reported at Sarasota, Florida, within the past hour and a wind gust to 56 mph (90 km/h) was recently reported at Albert Whitted Airport in St. Petersburg, Florida. The minimum central pressure estimated from data from a NOAA reconnaissance aircraft is 992 mb (29.30 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Debby can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC. WIND: Hurricane conditions are expected in the hurricane warning area and are possible in the hurricane watch area by early Monday, with tropical storm conditions expected to arrive later this evening and overnight. Tropical storm conditions will continue to spread northward over the tropical storm warning area along the Florida Gulf coast through tonight, and begin along portions of the tropical storm warning area along the Atlantic coast by late Monday. Tropical storm conditions are possible along the coast of South Carolina within the tropical storm watch area late Monday night. STORM SURGE: The combination of storm surge and tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Suwannee River to Ochlockonee River, FL...6-10 ft Yankeetown, FL to Suwannee River, FL...5-8 ft Ochlockonee River, FL to Indian Pass, FL...4-6 ft Tampa Bay...3-5 ft Middle of Longboat Key, FL to Yankeetown, FL...3-5 ft Bonita Beach, FL to Middle of Longboat Key, FL...2-4 ft Mouth of the St. Mary's River to South Santee River, SC...2-4 ft Charlotte Harbor...2-4 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. RAINFALL: Debby is expected to produce rainfall totals of 6 to 12 inches, with maximum amounts of 18 inches, across portions of northern Florida and southeastern North Carolina through Friday morning. This rainfall will likely result in areas of considerable flash and urban flooding, with significant river flooding expected. Across portions of southeast Georgia and South Carolina, 10 to 20 inches of rainfall, with local amounts to 30 inches, are expected through Friday morning. This potentially historic rainfall will likely result in areas of catastrophic flooding. For western Cuba, additional rainfall amounts of 1 to 2 inches, with localized higher amounts, will be possible through today. This will result in isolated to scattered areas of flooding. For a complete depiction of forecast rainfall and flash flooding associated with Tropical Storm Debby, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero TORNADOES: A few tornadoes are possible over central and northern Florida and southern Georgia tonight and Monday. The threat will spread northeastward into coastal Georgia and parts of South Carolina on Monday. SURF: Swells generated by Debby are expected to affect much of the Gulf coast of Florida through Monday. Swells will begin to affect the Southeast U.S. coast on Monday and continue through the middle of the week. These conditions are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1100 PM EDT. $$ Forecaster Brown