Tropical Storm Hanna closed in on the south-eastern US Thursday after hammering Haiti and was expected to surge into a hurricane, even as explosive Hurricane Ike gathered force in the Atlantic.
Hanna "has been an erratic storm. It's already done a lot of flooding (and) we are expecting it to strengthen slightly" before Friday, when it is due to pound the US states of North or South Carolina, US National Hurricane Center forecaster John Cangialosi told AFP.
Helicopters plucked desperate survivors from rooftops in the flooded Haitian city of Gonaives after Hanna claimed at least 61 lives, the third major storm to pound the poorest country in the Americas in as many weeks.
The storm, the fifth of the 2008 hurricane season, was moving across the Atlantic hundreds of miles from any land with winds of 215 kilometers (135 miles) per hour. It was too early to predict if "land areas might eventually be affected," the NHC said.
As of 0900 GMT, Hanna was moving north-west and was expected to pass east of the central and north-western Bahamas on Thursday "and will be near the south-east coast of the United States by Friday or Friday night," it said. Hanna had maximum sustained winds of about 110 kilometers (70 miles) per hour and rain bands and tropical storm force winds swirled as far as 465 km (290 miles) from its center early Thursday.