US: Tropical Storm Debby tracking eastward across the North Atlantic Ocean off the coast of South Carolina as of late Aug. 6 /update 9

Tropical Storm Debby is tracking eastward across the North Atlantic Ocean off the coast of South Carolina late Aug. 6. The storm previously made landfall as a Category 1 hurricane near Steinhatchee in the Big Bend region of the Florida Gulf Coast at around 07:00 EDT Aug. 5. As of 23:00, the system's center of circulation was approximately 80 km (50 miles) east-southeast of Savannah, Georgia.

Forecast models indicate that the system will strengthen slightly as it moves slowly eastward then northward Aug. 6-7 before making landfall northeast of Charleston in South Carolina late Aug. 7. The storm will weaken slightly but remain a tropical storm as it tracks northward over eastern South Carolina and across central North Carolina through early Aug. 9. The system will then likely weaken further and transition into a post-tropical depression as it tracks rapidly northeastward across Virginia, far northwestern Maryland, eastern Pennsylvania, southeastern New York, and central and northern Vermont in the US and far southeastern Quebec Province in Canada through late Aug. 11. Some uncertainty remains in the track and intensity forecast, and significant changes could occur over the coming days.

As of late Aug. 6, officials have issued the following watches and warnings:

Tropical Storm Warning

• North of the mouth of the Savannah River to Surf City, North Carolina

Tropical Storm Watch

• North of Surf City, North Carolina to Beaufort Inlet, North Carolina

Storm Surge Watch

• North of South Santee River, South Carolina to Cape Fear, North Carolina

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

Tropical storm conditions are forecast to continue along the coast of South Carolina within the tropical storm warning area through late Aug. 8 and within the tropical storm warning area in North Carolina from early Aug. 7.

The system will probably generate potentially historic rainfall totals of 25-50 cm (10-20 inches), with localized maximum amounts of 64 cm (25 inches), bringing areas of catastrophic flooding across portions of eastern South Carolina and southeast North Carolina through Aug. 9. Totals of 7.5-15 cm (3-6 inches) with localized amounts up to 20 cm (8 inches) are likely from central South Carolina to the upstate of South Carolina, northward into Southwest Virginia, portions of the Mid-Atlantic States, western and northern New York State into Northern New England through Aug. 10. This rainfall will likely result in areas of considerable flash and urban flooding, with river flooding possible. An additional scattered 2.5-7.5 cm (1-3 inches) of rainfall is possible across southeast Georgia through Aug. 6 and may aggravate ongoing flooding. Isolated tornadoes are possible over portions of coastal South Carolina and North Carolina through early Aug. 7.

Storm surge is possible along parts of the southeastern Atlantic coast over the coming days, with peak surges at high tide reaching 0.6-1.2 meters (2-4 feet) from South Santee River in South Carolina to Cape Fear in North Carolina. Swells from the storm will continue to affect the southeast US coast through around Aug. 11. These swells will likely cause life-threatening surf and rip current conditions.

Florida authorities declared a state of emergency for 61 of the state's 67 counties before the storm's arrival due to possible significant flooding. Officials issued mandatory and voluntary evacuation orders affecting thousands of people across counties in coastal areas of Florida, including mandatory evacuations in parts of Alachua, Citrus, Dixie, Franklin, Levy, Taylor, and Wakulla counties. Authorities in Savannah, Georgia, issued a curfew 22:00 Aug. 5-06:00 Aug. 6 due to the forecasted heavy rainfall. Officials have extended a curfew in Charleston, South Carolina that began at 23:00 Aug. 5 with conditions due to be reassessed at 07:00 Aug. 7 at the earliest. Georgia and South Carolina authorities declared a statewide State of Emergency Aug. 4 and Virginia authorities Aug. 6 ahead of Debby's approach.

Authorities have confirmed one fatality in Levy County, Florida, and another fatality in Moultrie, Georgia, due to falling trees. Traffic accidents in Florida due to adverse weather conditions have resulted in one fatality in Hillsborough County and another two fatalities in Dixie County. Reports indicate storm surge and resultant flooding along parts of the Big Bend coast Aug. 5, with water levels around 5.5 meters (18 feet) recorded at Cedar Key. The Sarasota Police Department had to evacuate around 500 people from flooded homes in the area. People living near the McGrady Dam in Colleton County, South Carolina, had to evacuate due to the potential for the dam to fail. Reports also indicate damage to buildings, power lines, and vehicles in Moncks Corner, South Carolina. following a suspected tornado. As of Aug. 6, more than 45,000 people across Florida remain without power.

Thousands of flights were canceled or delayed at airports across the region, including Charleston International Airport (CHS), Miami International Airport (MIA), Orlando International Airport (MCO), and Tampa International Airport, Aug. 5-6.

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.