Hurricane Dorian has shut down most major resorts in the Bahamas and forced authorities to evacuate much of the northern shore and low-lying islands.

The fierce Category 4 storm is set to unleash torrents of rain and howling winds but is projected to spin further away from the southeast US coast next week.

Forecasters expect Dorian, packing 240km/h winds, to hit the northwestern Bahamas on Sunday before curving upward.

The storm’s march north could spare the US a direct hit but still threatens Florida, Georgia and the Carolinas with powerful winds and rising ocean water that could cause potentially deadly flooding.

US President Donald Trump visited his private Virginia golf club for several hours as Hurricane Dorian bore down on the Southeast coastline of the US.

The president gave the impression as he left the White House on Friday that he would spend Saturday at Camp David with experts monitoring what has developed into a powerful Category 4 storm.

Mr Trump returned to Camp David later on Saturday, where he was to be briefed on the hurricane.

In the Bahamas, any remaining tourists were sent to government shelters in schools, churches and other buildings offering protection from the storm.

People line up to buy water at a store before the arrival of Hurricane Dorian, in Freeport, Bahamas. Photo: AAP

Ferry boat driver Margaret Bassett, 55, said her home was battened up and she was about to leave.

“We’re not taking no chances,” she said.

“They said evacuate, you have to evacuate. It’s for the best interests of the people.”

Over two or three days, the hurricane could dump as much as one metre of rain, unleash devastating winds and whip up an abnormal and dangerous rise in sea level called storm surge, according to private meteorologist Ryan Maue and some of the most reliable computer models.

Bahamas Prime Minister Hubert Minnis warned in a nationally televised briefing that the approaching Hurricane Dorian was “a devastating, dangerous storm”.

The storm-prone Bahamas on average faces a direct hit from a hurricane every four years, officials say.

Construction codes require homes to have metal reinforcements for roof beams to withstand winds into the upper limits of a Category 4 hurricane, and compliance is generally tight for residents who can afford it.

Poorer communities typically have wooden homes and are generally lower-lying, placing them at tremendous risk.

After walloping the islands, forecasters said the ever-strengthening Dorian was expected to dance up the southeast coastline, staying just off the shores of Florida and Georgia on Tuesday and Wednesday before skirting South Carolina and North Carolina on Thursday.

South Carolina Governor Henry McMaster declared a state of emergency on Saturday, mobilising state resources to prepare for the possibility the storm could still make landfall.

Mr Trump already declared a state of emergency in Florida and authorised the Federal Emergency Management Agency to co-ordinate disaster relief efforts.

The National Hurricane Center in Miami said the risk of strong winds and rising water will increase along the shores of Georgia and the Carolinas by midweek.

The centre also stressed that Dorian could still hit Florida, where millions of people have been in the storm’s changing potential path.

But after days of a forecast that put the state in the centre of expected landfalls, the hurricane’s turn northeast is significant.