Atlanta - Tropical Storm Beryl gained strength as it closed in on the southeastern US coast on Sunday, dumping rain and whipping up heavy surf from northeastern Florida to South Carolina.
The second named storm of the 2012 Atlantic hurricane season was approaching hurricane strength ahead of an expected landfall early on Monday, the US National Hurricane Centre said.
The powerful pack of thunderstorms has unleashed tropical storm conditions along the coast in northern Florida and Georgia, disrupting Memorial Day weekend plans for travellers and some beachgoers.
At 23:00, Beryl had sustained winds near 112km/h and was located about 121km south south-east of Brunswick, Georgia, the hurricane centre said.
An increase in wind speeds to 119km/h or more would make it a Category 1 hurricane on the five-step Saffir-Simpson intensity scale.
Forecasters, however, say they do not expect a significant change in Beryl's strength before it comes ashore and predict it will weaken to a depression by
Beryl was moving west toward the US coast at 16km/h, with tropical storm force winds near the coast of northeastern Florida.
The storm's approach led some vacationers in Georgia to leave early, said Alden Alias, the front desk manager at The King and Prince Hotel on St Simons Island, a popular coastal resort town.
"The waves are pretty big," she said. "The winds are starting to pick up."
City officials in Jacksonville cancelled Memorial Day ceremonies scheduled for Monday and closed some local parks as the storm drew closer. "I am encouraging all area residents to stay indoors and off the streets as the storm hits," said Jacksonville Mayor Alvin Brown.
Computer forecast models show Beryl moving on an eventual path back out over the Atlantic after coming ashore, posing no threat to US oil and gas installations in the Gulf of Mexico.
The storm is forecast to dump as much as 10-20cm of rain, with as much as 30cm in some areas, and threatens rip currents and possible coastal flooding, the hurricane centre said.
Beryl formed off the South Carolina coast late on Friday as a subtropical storm, a reference to the storm's structure. Subtropical storms usually have a broader wind field than tropical storms and shower and thunderstorm activity farther removed from the storm's centre.
It was reclassified as a tropical storm on Sunday.
Beryl followed the season's first major storm, Tropical Storm Alberto, which was the earliest-forming Atlantic storm since 2003.
The Atlantic hurricane season officially runs from 1 June to 30 November, though it is not unusual for storms to form earlier.