More than a million people were ordered Monday to evacuate the path of Hurricane Florence as the Category 4 storm packing winds of 195 kilometres per hour bore down on the East Coast of the United States.
South Carolina Governor Henry McMaster told up to one million residents of the state's eastern coast to leave their homes ahead of the powerful storm's arrival on Thursday.
The governor of neighbouring North Carolina also ordered an evacuation of the Outer Banks and parts of coastal Dare County while a state of emergency was declared in Virginia.
"This is a very dangerous hurricane," McMaster said, adding that the evacuation order for coastal counties was "mandatory, not voluntary."
"We do not want to risk one South Carolina life in this hurricane," the governor told a press conference. "We're liable to have a whole lot of flooding."
Hurricane Florence has the potential to bring catastrophic flooding to areas of the eastern United States already soaked by heavy rain and may be the strongest storm to hit the region in decades.
A Category 4 on the five-level Saffir-Simpson hurricane scale, Florence was 925 kilometres south-southeast of Bermuda and the center of the hurricane was forecast to pass between Bermuda and the Bahamas on Tuesday and Wednesday, the National Hurricane Center (NHC) said in its latest advisory.
"Florence has continued to rapidly strengthen," the NHC said at 1500 GMT. "Florence is expected to be an extremely dangerous major hurricane through Thursday."
US east coast braces for Hurricane Florence. Source: RTV
President Donald Trump tweeted out a message to residents in the storm's path, urging them to heed the warnings of state and local officials.
"To the incredible citizens of North Carolina, South Carolina and the entire East Coast - the storm looks very bad!" wrote the president, who cancelled a planned rally Friday in Jackson, Mississippi in light of the approaching storm.
"Please take all necessary precautions. We have already began mobilising our assets to respond accordingly, and we are here for you!"
Storm surge and hurricane watches
At a hardware store in downtown Charleston, South Carolina, store manager John Johnson said the rush on batteries, flashlights, plastic tarps and sandbags began Friday.
"From eight o'clock 'til two we were slammed," said Johnson, who sold scores of bags of sand over the weekend, saving just a few to barricade the store's own doors.
"We were nonstop."
On Monday afternoon, nurse Barbara Mack was using a small shovel to fill sandbags at a public works facility in Charleston -- but she saw a silver lining in the hurricane preparations.
"This is good exercise," she quipped. "This is probably the only exercise I get this week."
Walker Townsend, at right, from the Isle of Palms, S.C., fills a sand bag while Dalton Trout, in center, holds the bag at the Isle of Palms municipal Source: AAP
Storm surge and hurricane watches may be issued Tuesday morning for portions of southeastern US states, the NHC said.
On its current track, Florence is expected to slam the Carolinas and Virginia the hardest.
Virginia Governor Ralph Northam's office warned of "catastrophic inland flooding, high winds and possible widespread power outages," cautioning that the deadliest risk would come from flooding.
The US Navy said it was preparing to send about 30 ships stationed in Virginia out to sea.
The vessels will get underway from Naval Station Norfolk and Joint Expeditionary Base Little Creek to avoid potential damage from winds and tidal surges, Pentagon spokesman Colonel Rob Manning said.
Heavy rain in the Washington area over the weekend has already led to flooding in historic Alexandria, Virginia, and the National Weather Service issued a flood watch for part of the Potomac River.
Two more hurricanes
Florence is currently moving west at around 20km/h.
North Carolina Governor Roy Cooper's office said Florence is already being felt along the state's coast, with large sea swells resulting in life-threatening rip currents and surf.
"This is a huge storm," said Robert Woodward, chairman of the Dare County Board of Commissioners, predicting 15 to 20 inches of rain.
"Never have we seen quite this type of a storm approach us."
At this height of the Atlantic hurricane season, Florence was being trailed on east-to-west paths by two other hurricanes, Helene and Isaac.
People shop at the Harris Teeter, filling up on water and supplies as Hurricane Florence becomes a threat to the coast Monday, Sept. 10 Source: AAP
Helene -- 600 kms west of the Cape Verde islands off the African coast -- had winds up to 105 mph (165 kph), and was expected to continue moving west-northwest for another couple of days, the NHC said in its 1500 GMT bulletin.
Hurricane Isaac -- which late Sunday became the fifth hurricane of the season -- is heading west towards the Caribbean.
At 1500 GMT, Isaac, which the NHC called a small hurricane, was about 1,855 kms east of the Windward Islands -- a region still recovering from last year's powerful Hurricane Maria -- with maximum sustained winds near 75 mph (120 kph).
Maria -- which killed at least 3,057 people, most in Puerto Rico -- is believed to be the third-costliest tropical cyclone on record.
The costliest hurricane in US history, Katrina was a Category 3 storm when it made landfall on the Gulf Coast in August 2005 -- claiming an estimated 1,833 lives.
