By Letitia Stein
TAMPA, Fla. (Reuters) - Florida braced for flooding and strong winds as Tropical Storm Colin churned toward the state's northern Gulf Coast on Monday, and was expected to make landfall later in the day before crossing the U.S. Southeast.
Tropical storm warnings were in effect for the state's central and northern coastlines as Colin, which was expected to rumble through the Gulf of Mexico, gusted to around 50 miles per hour (85 kph), the National Hurricane Center in Miami said.
A tropical storm watch extended to coastal Georgia and South Carolina, which were expected to be in the storm's path overnight Tuesday. Forecasters warned of dangerous surf conditions and the potential for flooding.
The storm, expected to speed up later in the day, was on track to reach the Big Bend region in the northern part of the state on Monday afternoon or evening.
Fears of storm surges exacerbated by high tide prompted voluntary evacuations in low-lying areas of Franklin County, Florida, about 70 miles (112 kilometers) southwest of Tallahassee.
Flooding and isolated tornadoes threatened densely populated communities from south of the Tampa Bay region through Jacksonville, according to the National Weather Service.
Colin is part of a brisk start to the Atlantic hurricane season running through Nov. 30. Over the U.S. Memorial Day holiday weekend, the Carolinas were lashed by heavy rain and winds from Tropical Storm Bonnie.
At 8 a.m. EDT (noon GMT) on Monday, Colin was located about 315 miles (505 kilometers) west-southwest of Tampa. It was moving north-northeast at 14 miles per hour (22 kilometers per hour).
(Editing by Jeffrey Benkoe)