Gulf of Mexico: Tropical Storm Debby tracking north-northwestward toward Florida, US, as of Aug. 4 /update 4

Tropical Storm Debby is tracking north-northwestward over the eastern Gulf of Mexico Aug. 4. As of 11:00 EDT, the system's center of circulation was approximately 210 km (130 miles) west-southwest of Tampa, Florida.

Forecast models indicate that the system will strengthen into a category 1 hurricane as it tracks northward and then north-northeastward over the northeastern Gulf of Mexico before making landfall over the Big Bend region of the Florida Gulf coast southeast of Tallahassee early Aug. 5. The system is forecast to weaken but remain a tropical storm as it tracks northeastward then east-northeastward across southern Georgia Aug. 5-6, before briefly strengthening as it tracks northeastward along the South Carolina coast Aug. 7. The storm is expected to weaken into a tropical depression as it continues northeastward further inland over South Carolina and into North Carolina through early Aug. 9. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming days.

As of Aug. 4, officials have issued the following watches and warnings:

Hurricane Warning

• Florida coast from the Suwannee River to the Ochlockonee River

Hurricane Watch

• Florida coast west of the Ochlockonee River to Indian Pass

• Florida coast south of the Suwannee River to Yankeetown

Tropical Storm Warnings

• Dry Tortugas

• Florida coast south of the Suwannee River to East Cape Sable

• Florida coast west of the Ochlockonee River to Indian Pass

Tropical Storm Watches

• Florida coast west of Indian Pass to Mexico Beach

• Georgia and South Carolina coast from the mouth of the St. Mary's River to the South Santee River

Storm Surge Warning

• Florida coast from the middle of Longboat Key northward to Indian Pass including Tampa Bay

Storm Surge Watch

• Florida coast from Bonita Beach northward to the middle of Longboat Key, including Charlotte Harbor

• Georgia and South Carolina coast from the Mouth of the St. Mary's River to the South Santee River

Authorities will likely issue new warnings throughout the system's progression in the coming days.

Hurricane conditions are expected in the hurricane warning area and are possible in the hurricane watch areas early Aug. 5, with tropical storm conditions expected late Aug. 4. Tropical storm conditions are expected to spread northward over the tropical storm warning areas Aug. 4. Tropical storm conditions are possible in the watch area in the Florida Panhandle Aug. 5 and along the coast of Georgia and South Carolina late Aug. 5.

The system is expected to generate rainfall totals of up to 15-30 cm (6-12 inches), with localized maximum amounts of 45 cm (18 inches), over parts of northern Florida through early Aug. 9. These rains could result in flash, urban, and riverine flooding in affected areas. Totals of 25-50 cm (10-20 inches) with localized amounts up to 76 cm (30 cm) are expected in parts of southeast Georgia and South Carolina through early Aug. 9. This potentially historic rainfall may result in areas of catastrophic flooding. Isolated tornadoes are possible through early Aug. 5 mainly over western and northern Florida and southern Georgia..

Storm surge is possible along parts of the affected Florida coast, with peak surges at high tide reaching 1.8-3 meters (6-10 feet) from Suwannee River to Ochlockonee River, 1.2-2.1 meters (4-7 feet) from Yankeetown to Suwannee River, 1.2-1.8 meters (4-6 feet) from Ochlockonee River to Indian Pass, and 0.6-1.5 cm (2-5 feet) over other adjacent coastal areas. Swells generated by the storm are expected to affect much of Florida's Gulf coast through Aug. 5 and will begin to affect the southeast US coast Aug. 5 and continue through around Aug. 7. These swells are likely to cause life-threatening surf and rip current conditions.

Florida authorities declared a state of emergency for 54 of the state's 67 counties before the storm due to possible significant flooding. Mandatory and voluntary evacuation orders affecting thousands of people have been issued across nine counties in coastal areas of Florida, including mandatory evacuations in parts of Citrus, Franklin, and Levy counties. Flight delays and cancellations at airports are occurring across parts of Florida as of Aug. 4. Major airports such as Orlando International Airport (MCO) and Tampa International Airport (TPA) have announced they plan to stay open during the passing of the storm; however, dozens of flights have been canceled and delayed Aug. 4.

Sustained heavy rainfall could trigger flooding in low-lying areas and locations with easily overwhelmed drainage systems. Localized evacuations, flash flooding, and landslides are possible in hard-hit regions.

Inclement weather could trigger localized business, transport, and utility disruptions, rendering some bridges or roadways impassable. Flight disruptions at regional airports and temporary port closures are also possible. Stagnant pools of water during and after flooding may increase the incidence of insect—and waterborne diseases, such as dengue fever, cholera, and malaria. Exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.