Tropical Storm Debby Dumps Flooding Rains As It Inches Up Atlantic Coast

Tropical Storm Debby has moved into the Southeast U.S. , bringing torrential downpours and flooding. The storm, which made landfall on the Gulf Coast of Florida as a Category 1 hurricane, has already claimed at least five lives and caused flash flooding in historic Savannah, Georgia, and Charleston, South Carolina.

Despite being downgraded to a tropical storm with wind speeds near 45 mph, meteorologists warn that the storm's rainfall capacity makes it extremely dangerous.

"Tropical cyclones always produce heavy rain, but normally as they're moving, you know, it doesn't accumulate that much in one place," said Richard Pasch , a senior hurricane specialist with the National Hurricane Center .

Debby is expected to produce potentially historic rainfall totals of 10 to 20 inches, with maximum amounts of 25 inches, bringing areas of catastrophic flooding across portions of southeast Georgia, the eastern half of South Carolina, and southeast North Carolina through Friday.

Charleston, South Carolina, is particularly vulnerable due to its geography. Much of the historic peninsula lies on low marshland filled in over the years by dirt and debris. With the Ashley and Cooper rivers on either side, the city is hard to drain, especially during high tide or when the winds blow onshore from the Atlantic Ocean. The city's emergency plan includes sandbags for residents, opening parking garages so residents can park their cars above floodwaters, and an online mapping system that shows which roads are closed by flooding.

President Joe Biden has approved an emergency declaration for much of Georgia, authorizing the Federal Emergency Management Agency to mobilize equipment and resources to protect lives, property, and public health, including coordinating evacuations and shelters.