Some coastal flooding is still likely from the storm's surge, the hurricane center says, and unrelated rains could cause flooding in parts of the Carolinas and Virginia.
The Category 4 storm remains near the Bahamas tonight and is likely to batter the islands "well into Friday," the agency says.
Updated at 9:10 p.m. ET
The National Hurricane Center, in its latest bulletin, says the powerful Category 4 Hurricane Joaquin is battering the Bahamas and a tropical storm warning has been issued for eastern Cuba.
The storm has maximum sustained winds of 130 mph, the NHC says, and it's moving west-southwest at 5 mph.
The Associated Press writes:
"As of 8 p.m. EDT, the storm was located about 25 miles (45 kilometers) east-southeast of Long Island [in the Bahamas] after passing over Samana Cays, Bahamas. ...
"While Samana Cays is usually uninhabited, eight to 10 people were working there, staying in temporary housing, when the storm hit, said Parliament member Alfred Gray."
Brian McNoldy, a hurricane forecaster for the University of Miami's Rosenstiel School of Marine and Atmospheric Science who also writes for The Washington Post's weather blog, said tonight:
"Tracking through the warm ocean waters of the Bahamas, Hurricane Joaquin exploded in intensity while becoming a dangerous Category 4 storm Thursday. But, at the same time, the forecast track for Joaquin shifted markedly east and it is now very likely the storm will remain out to sea rather than slamming into the East Coast.
"While Joaquin may remain offshore, parts of the East Coast remain at risk for flooding from a predecessor surge of moisture streaming up the eastern seaboard Friday into Saturday."