Hurricane Isaias has made landfall near Ocean Isle Beach, North Carolina, according to the US National Hurricane Center.
The hurricane touched down just after 11pm (03:00 GMT) on Monday with maximum sustained winds of 85 mph (136 km/h).
Coastal shops and restaurants closed early, power began to flicker at oceanfront hotels and even the most adventurous of beachgoers abandoned the sand Monday night as newly restrengthened Hurricane Isaias sped towards the Carolinas.
The US National Hurricane Center warned oceanside home dwellers to brace for storm surge up to 5 feet (1.5 metres) and up to 8 inches (20 centimetres) of rain in spots, as Isaias moved up the coast.
The Carolinas weren’t the only states at risk.
“All those rains could produce flash flooding across portions of the eastern Carolinas and mid-Atlantic, and even in the northeast US,” said Daniel Brown, senior hurricane specialist at the US National Hurricane Center.
A tropical storm warning extended all the way up to Maine, where flash flooding was possible in some areas on Wednesday.
The center also warned of possible tornadoes in North Carolina on Monday night and early Tuesday, and from eastern Virginia to southern New England later Tuesday.
Isaias will likely regain hurricane strength as it moves up the United States East Coast towards major cities such as Washington, Philadelphia and New York.
It poses an immediate threat to a stretch of coastline that includes the South Carolina tourist resort of Myrtle Beach and the North Carolina port city of Wilmington.
Though Isaias will likely weaken before dousing the US Northeast on Tuesday, New York City is already bracing for a storm surge in lower Manhattan, mindful of the devastation caused by Superstorm Sandy in 2012.