Dorian near US coast, storm surge feared

Hurricane Dorian is creeping up the Southeastern coast of the US and millions of people have been ordered to evacuate as forecasters said near-record levels of seawater and rain could inundate Georgia and the Carolinas.

The storm, which ravaged the Bahamas with more than a full day of devastating wind and rain, had weakened substantially - from a Category 5 storm to a Category 2 - but still had dangerously high winds and threatened to swamp low-lying regions from Georgia to southeastern Virginia as it moved northward.

"We will experience hurricane-force winds, in at least gusts," South Carolina Governor Henry McMaster said at a news conference Wednesday. Even if the hurricane doesn't end up hitting the state directly, he said, "there's still going to be wind and water and if you're in the coastal area, that water can be treacherous."

Dorian appeared likely to get dangerously near Charleston, which is particularly vulnerable since it is located on a peninsula. A flood chart posted by the National Weather Service projected a combined high tide and storm surge around Charleston Harbor of 3.1 metres; the record, four metres, was set by Hugo in 1989.

Stores and restaurants were boarded up with wood and corrugated metal in the city's historic downtown, and about 830,000 people were under mandatory evacuation orders on the South Carolina coast. More than 400 people were in state-operated shelters statewide, and more were expected.

Georgia's coastal islands were also at risk, Governor Brian Kemp said Wednesday.

"We are very worried, especially about the barrier islands getting cut off if we have these storm surges at the same time as ... the high tides," Kemp said.

Duke Energy said Dorian could cause more than 700,000 power outages in eastern regions of North Carolina and South Carolina, and Georgia Power said about 2,800 homes and businesses were already without electricity.

The Navy ordered ships at its huge base in Norfolk, Virginia, to head out to sea for safety, and warplanes at Langley Air Force Base in Hampton, Virginia, were being moved inland to Ohio.

Weaker but bigger since it slammed the Bahamas with 295 km/h winds earlier this week, Dorian was moving along Florida's northeastern coast at 13 km/h late Wednesday afternoon. Forecasters said it had maximum sustained winds of 177 km/h and was centred about 241 kilometres south of Charleston.

A hurricane warning covered about 805 kilometres of coastline, and authorities warned about 3 million residents to get away before the water and wind rose with Dorian's approach.