More than a million people were under evacuation orders in the eastern United States Tuesday, where powerful Hurricane Florence threatened catastrophic damage to a region popular with vacationers and home to crucial government institutions.
The menacing Category 4 storm packed winds of 130 miles (215 kilometers) per hour over the Atlantic.
"This is one of the worst storms to hit the East Coast in many years," President Donald Trump warned on Twitter. "Please be prepared, be careful and be SAFE!"
South Carolina Governor Henry McMaster ordered as many as one million coastal residents to leave their homes ahead of the storm's projected arrival on Thursday. Schools in 26 of the state's 46 counties were ordered closed from Tuesday.
The governor of neighboring North Carolina ordered an evacuation of the Outer Banks, barrier islands that are a popular tourist destination, and parts of coastal Dare County.
Virginia, home to major government and military facilities, declared a state of emergency and 245,000 coastal residents there were ordered to evacuate by 8:00 am Tuesday including from the Eastern Shore, another popular beachfront getaway destination.
"Hurricane Florence has the potential to cause catastrophic flooding, especially in our coastal areas," Virginia Governor Ralph Northam said, activating the National Guard. "This evacuation is for the safety of thousands of Virginians living in that zone. But the effects of this storm will be felt statewide, and I encourage everyone in Virginia to prepare now."
In neighboring Maryland Governor Larry Hogan said that, in declaring an emergency, his state was readying for potentially "historic and catastrophic rainfall, life-threatening flooding, and high winds."
Trump approved emergency declarations for the Carolinas, a standard move allowing the release of federal funds and equipment to aid in protection and recovery efforts.
The president said the "federal government stands by, ready to assist 24/7."
Hurricane Florence has the potential to bring disastrous flooding to areas of the eastern United States already soaked by heavy rain. It may be the strongest storm to hit the region in decades.
On the five-level Saffir-Simpson hurricane wind scale Florence is a Category 4, meaning "catastrophic damage" can occur."
Florence was about 405 miles south of Bermuda and its center was forecast to move between Bermuda and the Bahamas through Wednesday, before approaching the coast of North Carolina or South Carolina on Thursday, the National Hurricane Center (NHC) said in its 8:00 am (1200 GMT) advisory.
By Saturday, total rainfall could accumulate to 20 inches (51 centimeters) -- or even 30 inches in places -- in parts of the Carolinas and Virginia, the NHC said.
Although the maximum sustained winds of Florence had decreased, re-strengthening is forecast "and Florence is expected to be an extremely dangerous major hurricane through Thursday night," the hurricane center said.
- Sandbagging –
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."
Nurse Barbara Mack was using a small shovel to fill sandbags at a public works facility in Charleston.
"This is probably the only exercise I get this week," she quipped.
Also out for sandbags was Deborah LaRoche. Half her supply was going to barricade a basement soup kitchen she managed, and the other half to protect her own home on nearby Johns Island.
She and her husband would decide Tuesday morning whether to evacuate their family of two kids and a dog, said LaRoche. Having grown up in storm-prone Florida, she said she's careful not to underestimate any hurricane.
"It doesn't matter what happened in (previous) storms," said LaRoche, a social services director. "This one is different."
Early Tuesday, authorities began closing inbound lanes of Interstate 26 into Charleston to help facilitate the traffic flow of those wanting to get out.
The US Navy was sending about 30 ships stationed at its major bases in Virginia out to sea.
The vessels would get underway from Naval Station Norfolk and Joint Expeditionary Base Little Creek to avoid potential damage from winds and tidal surges, said Colonel Rob Manning, a Pentagon spokesman.
United States Coast Guard officials also ordered commercial vessels and pleasure craft to take precautions.
Heavy rain in the Washington area over the weekend has already led to flooding in historic Alexandria, Virginia, which on Tuesday was under a coastal flood warning, along with the shoreline of Washington.
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.
"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 storms, Helene and Isaac.
Helene -- 620 miles west of the Cape Verde islands off the African coast -- had winds up to 110 miles per hour, and was expected to continue moving west-northwest for several more days, the NHC said.
Isaac -- which late Sunday became the fifth hurricane of the season, but was later downgraded to a tropical storm -- is heading west toward the Caribbean.
Despite the slight drop in maximum sustained winds to 70 miles per hour, Isaac is expected to be at or near hurricane strength as it passes near land later this week.
The storm was about 880 miles east of the Lesser Antilles -- a region still recovering from last year's powerful Hurricane Maria.