Tropical Storm Debby Update: Flooding and Record Rainfall Threaten the Southeast Coast

Tropical Storm Debby early on August 7, 2024.NOAA / National Hurricane Center

Tropical Storm Debby is taking a breather in the western Atlantic, but has not yet fully finished flooding the Carolina coast and is slowly moving north, according to the National Hurricane Center. It still poses a "threat of significant flooding" to parts of the Carolinas. 

The center said Debby is expected to return to the South Carolina coast "either tonight or early Thursday." "Further rapid northward and north-northeastward movement is expected across the Carolinas and the U.S. Mid-Atlantic region on Thursday and Friday. 

"Some strengthening is possible today or tonight before the center of Debby reaches the South Carolina coast. Weakening is expected to begin on Thursday after the center moves inland."

The center added that Debby could move through central North Carolina, through Virginia and into the Washington area by Saturday. 

Debby was located about 105 miles south-southeast of Charleston, South Carolina, and about 90 miles east of Savannah, Georgia, early Wednesday. It was moving east at just over 5 miles per hour, with maximum sustained winds of 45 mph.

"Tropical storms always bring heavy rain, but they don't usually accumulate that much rain in one place as they move," said Richard Pash of the hurricane center. "But when they're moving so slowly, that's the worst case scenario." Forecasters said there will be a lull in the rains as dry periods occur between bands near the center of the poorly organized storm. But some bands are violent and move in the same place. With the Debbie River swirling just offshore, heavy rain is expected to move into areas of South Carolina and North Carolina that have already experienced $2 billion in flooding in eight years. The Miami hurricane center said Debbie is "expected to bring an additional 3 to 9 inches of rain, with locally higher rainfall amounts, resulting in maximum storm winds reaching 25 inches in South Carolina and 15 inches in southeastern North Carolina, with further storm winds." Major flooding will extend into parts of South Carolina and southeastern North Carolina through Friday. "3 to 7 inches of rain, with localized amounts of up to 10 inches, is expected by Friday from the South Carolina Piedmont north into parts of Virginia. This rainfall could cause areas of significant flash flooding and urban flooding, and river flooding. "2 to 4 inches of rain, with localized amounts up to 6 inches, is expected by Saturday morning from northern Maryland through upstate New York and Vermont. This could cause river flooding as well as significant flash flooding and urban flooding." 

The slow-moving storm soaked coastal cities in Georgia and South Carolina late Monday and Tuesday, spawning tornadoes and inundating streets with waist-deep floodwaters.

A man stands in front of his home looking at a street flooded by Tropical Storm Debby on August 06, 2024 in Charleston, South Carolina.

Some areas along the North Carolina coast, including Wilmington and the Outer Banks, are prone to flooding. Virginia could feel the effects of strong winds, heavy rains, and flooding. 

Rainfall in some parts of the Carolinas could approach the historic flooding amounts caused by Hurricane Matthew in 2016. Two years later, many of these records were broken by Hurricane Florence. Both storms claimed dozens of lives. Debby's rains are believed to be responsible for at least five deaths, four in Florida, including two children, and one in Georgia. As of early Wednesday morning, 44,000 customers in Florida were still without power, according to PowerOutage.us.  

Charleston and Savannah were hit by flooding through Tuesday, leading to curfews and police road closures. Dozens of streets in Charleston were closed due to flooding that occurs several times a year due to rising sea levels. In one Savannah neighborhood, firefighters used boats to evacuate some residents and delivered bottled water and other supplies to those who refused to evacuate by walking through floodwaters. Michael Jones said water entered his home Monday night, flipping his refrigerator and floating his furniture. Outside, the water was everywhere and seemed too deep to escape to safety, so Jones spent a sleepless night at his kitchen table until door-to-door firefighters arrived by boat Tuesday morning. "It was hell all night," Jones said. Charleston Mayor William Cogswell said the road closures saved businesses and homes from unnecessary damage and averted the need for flood rescues. "We especially don't need fools driving through water and causing property damage," Cogswell said. North Carolina and Virginia both declared states of emergency. "Debby's impacts are widespread and neighboring states face significant challenges," Virginia Gov. Glenn Youngkin said. Green Pond, in rural Colleton County, South Carolina, recorded a record rainfall of just over 350 mm. Nearby levees flooded but did not break, but many roads were blocked by washed-out trees and debris, according to Deputy Fire Chief David Green of the county. Nearly a foot of rain fell along the coast from Charleston to Savannah, with the National Weather Service reporting 170 mm of rain on Monday alone. That's already the equivalent of a month's worth of rain in one day, and in August 2023, the city received 140 mm of rain in one month. Tornadoes downed trees and damaged several homes on Kiawah and Edisto Islands. Crooked Hammock Brewery in North Myrtle Beach, South Carolina, decided to close early on Tuesday. "Flash flooding is completely unpredictable and we want our employees and guests to stay home and be safe," said marketing coordinator Georgina Dimitriadis. 

Far north in New York City, severe storms that meteorologists said were intensified by Debby caused some roads and highways to flood, making cars impossible to drive. The National Weather Service issued a citywide flood warning until noon Wednesday.

Emergency workers warned of possible flash flooding and flew drones with loudspeakers over parts of New York, urging people in basements to evacuate at any time. Police said Monday that about 500 people had been rescued from flooded homes in Sarasota, Florida. More than 200 people were rescued north of Sarasota, according to Manatee County officials. Officials said it could take two weeks to fully assess the damage in some parts of north-central Florida as they wait for the river to peak. "We're seeing tributaries rising," he said. This is inevitable. How much? "We'll see how it goes. It may not flood today, but it could flood tomorrow," Florida Gov. Ron DeSantis said Tuesday. Georgia Gov. Brian Kemp also warned of further rainfall and flooding, saying, "Don't be fooled by this storm." President Biden authorized a state of emergency and provided federal disaster assistance to Florida, Georgia and South Carolina. Debby made landfall on the Gulf Coast of Florida early Monday as a Category 1 hurricane before weakening to a tropical storm.