What to Know
Florence now expected to hover off the southern North Carolina coast from Thursday night until landfall Saturday morning
States of emergency were declared in North and South Carolina and Virginia by President Trump. Georgia is also threatened
Florence's projected path includes half a dozen nuclear power plants, pits holding coal-ash and other industrial waste, and hog farms
Hurricane Florence put a corridor of more than 10 million people in the crosshairs Wednesday as the storm closed in on the Carolinas, uncertainty over its projected path spreading worry across a widening swath of the Southeast.
Faced with new forecasts that showed a more southerly threat, Georgia's governor joined his counterparts in Virginia and North and South Carolina in declaring a state of emergency, and some residents who had thought they were safely out of range boarded up their homes.
The National Weather Service's best guess was that the hurricane would blow ashore Saturday morning along the North Carolina-South Carolina line, then push its rainy way westward with a potential for catastrophic inland flooding.
At 11 p.m. ET, Florence was downgraded to a Category 2 hurricane, but officials still warned of a powerful storm carrying dangerous amounts of rain.
The National Weather Service said 5.25 million people live in areas under hurricane warnings or watches, and 4.9 million live in places covered by tropical storm warnings or watches.
At the White House, President Donald Trump both touted the government's readiness and urged people to get out of the way of Florence.
"Don't play games with it. It's a big one," he said.
Duke Energy, the nation's No. 2 power company, said Florence could knock out electricity to three-quarters of its 4 million customers in the Carolinas, and outages could last for week. Workers are being brought in from the Midwest and Florida to help in the storm's aftermath, it said.
Boarding up his home in Myrtle Beach, Chris Pennington watched the forecasts and tried to decide when to evacuate.
"In 12 or 18 hours, they may be saying different things all over again," he said.
Computer models of exactly what the storm might do varied, adding to the uncertainty. In contrast to the hurricane center's official track, a highly regarded European model had the storm turning southward off the North Carolina coast and coming ashore near the Georgia-South Carolina line.
Reacting to the possibility of a more southerly track, Georgia Gov. Nathan Deal declared an emergency but did not immediately order any evacuations.
"I ask all Georgians to join me in praying for the safety of our people and all those in the path of Hurricane Florence," Deal said.
The shift in the projected track spread concern to areas that once thought they were out of range. In South Carolina, close to the Georgia line, Beaufort County emergency chief Neil Baxley told residents they need to prepare again for the worst just in case.
"We've had our lessons. Now it might be time for the exam," Baxley said late in the morning.
Their entire neighborhood evacuated in Wilmington, North Carolina, David and Janelle Garrigus planned to ride out Florence at their daughter's one-bedroom apartment in Charlotte. Unsure of what they would find when they return home, the couple went shopping for a recreational vehicle.
"We're just trying to plan for the future here, not having a house for an extended period of time," David Garrigus said.
Melody Rawson evacuated her first-floor apartment in Myrtle Beach and arrived at Atlanta Motor Speedway in Hampton, Georgia, to camp for free with three other adults, her disabled son, two dogs and a pet bird.
"We hope to have something left when we get home," she said.
Forecasters worried the storm's damage will be all the worse if it lingers on the coast. The trend is "exceptionally bad news," said University of Miami hurricane researcher Brian McNoldy, since it "smears a landfall out over hundreds of miles of coastline, most notably the storm surge."
With South Carolina's beach towns more in the bull's-eye because of the shifting forecast, Ohio vacationers Chris and Nicole Roland put off their departure from North Myrtle Beach to get the maximum amount of time on the sand. Most other beachgoers were long done.
"It's been really nice," Nicole Roland said. "Also, a little creepy. You feel like you should have already left."
North Carolina Gov. Roy Cooper warned in blunt terms of the looming danger, saying that everyone in the state would feel the storm's effects and needed to take it seriously.
"My message is clear: Disaster is at the doorstep and is coming in," Cooper said during a morning briefing.
As of 11 p.m., the storm was centered 280 miles (455 kilometers) east southeast of Wilmington, North Carolina, and was moving northwest at 17 mph (28 kph). Its maximum sustained winds have dropped slightly to 110 mph (175 kph).
Waves 83 feet high were measured near the eye of Florence, according to a tweet from the National Hurricane Center. But that was out in the open ocean, where deeper water means bigger waves.
"This is not going to be a glancing blow," Jeff Byard, an administrator with the Federal Emergency Management Agency, warned. "This is going to be a Mike Tyson punch to the Carolina coast."
He said that Wednesday was the last day for people under evacuation orders to get out safely. Byard assured people that the agency has all the resources it needs to react to the natural disaster.
As of Tuesday, about 1.7 million people in North and South Carolina and Virginia were under warnings to evacuate the coast, and hurricane watches and warnings extended across an area with about 5.4 million residents. Cars and trucks full of people and belongings streamed inland.
For many of those under evacuation orders, getting out of harm's way has proved difficult, as airlines canceled flights and motorists had a hard time finding gas.
Michelle Stober loaded up valuables at her home on Wrightsville Beach to drive back to her primary residence in Cary, North Carolina.
"This morning I drove around for an hour looking for gas in Cary. Everyone was sold out," she said.
Those who managed to escape are worried about what they left behind and the possibility of floodwaters destroying everything they own.
"I'm just scared cause I want a house to come home to," said Wilmington, North Carolina, resident Joseph LaFontaine, whose family evacuated north to stay will family in New York.
Florence is the most dangerous of three tropical systems in the Atlantic. Tropical Storm Isaac was expected to pass south of Puerto Rico, Haiti, the Dominican Republic and Cuba, while Hurricane Helene was moving northward away from land. Forecasters also were tracking two other disturbances, including Subtropical Storm Joyce.
The coastal surge from Florence could leave the eastern tip of North Carolina under more than 9 feet (2.75 meters) of water in spots, projections showed. The Navy, Air Force and Army were moving ships and aircraft out of harm's way. Thousands of Marines and their families evacuated from Camp Lejeune, leaving the rest to dig in ahead of what could be a direct hit.
Florence's projected path includes half a dozen nuclear power plants, pits holding coal-ash and other industrial waste, and numerous hog farms that store manure in huge lagoons.
In Wilmington, resident Michael Wilson fortified his home against the wind and rain, and worried.
"The biggest thing is you're always worried about yourself and friends and family — and whether they'll have a place to come back to," he said.