As Tropical Storm Debby chugs north along the Eastern Seaboard, units of the National Park System, facing a foot or more of rainfall and associated flooding, shuttered their operations and prepared for the aftermath.

Congaree National Park in South Carolina closed its doors on Monday, as did Fort Pulaski National Monument in Georgia, while Cumberland Island National Seashore along Georgia's coast planned to be closed Wednesday and Thursday.

"Due to the slow-moving nature of this storm, the National Weather Service has placed much of the region around Congaree National Park under a moderate to high risk of excessive rainfall Tuesday and Wednesday," the National Park Service said Monday. "Current projections are calling for the area in the immediate vicinity of the park to receive between 10-15 inches of rain through Friday of this week, and there is a moderate to high probability that flash flooding will occur, especially within the next 24-36 hours.

"...The Longleaf and Bluff Campgrounds are closed to reservations through Friday, August 9. The park is scheduled to reopen at 7:00 a.m. on Friday, August 9 if conditions allow," the agency added.

Also closing because of the storm were Fort Sumter and Fort Moultrie National Historical Park, Charles Pinckney National Historic Site, Fort Frederica National Monument, Moores Creek National Battlefield, Reconstruction Era National Historical Park, and Timucuan Ecological and Historic Preserve. 

Meteorologists at AccuWeather warned of the flooding potential from the storm.

“Debby will be recognized as the next billion-dollar weather disaster in the United States,” said AccuWeather Chief Meteorologist Jon Porter. “We do not forecast an extreme risk to lives and property from flooding very often. Flooding disasters are possible in multiple communities this week. People need to be prepared for potentially catastrophic flooding. When all is said and done, in fact, there could be tens of billions of dollars in total damage and economic impact from Debby.” 

The National Hurricane Center said the storm will carry "potentially historic heavy rainfall across eastern South Carolina through Friday" that "will likely result in areas of catastrophic flooding. Heavy rainfall will likely result in flooding impacts from northern North Carolina through portions of mid-Atlantic states and southern New England through Sunday morning."

The tropical storm also was expected to generate "dangerous storm surge" along the coastline from northeastern Georgia into North Carolina through Thursday.