WASHINGTON - Florence exploded into a potentially catastrophic Category 4 hurricane Monday as it closed in on North and South Carolina. The National Weather Service says Hurricane Florence continues to increase in strength, size, and forward speed, with max winds now 140 mph.
The National Weather Service says Florence could reach Category 5 status in the next couple of days.
In preparation, officials in Virginia and Maryland have declared states of emergency ahead of the storm.
Governor Northam has ordered the coastal evacuation of Virginia's Zone A, the lowest-lying areas of Coastal Virginia and the Eastern Shore, effective 8 a.m. September 11.
Maryland Gov. Larry Hogan held a press conference on Monday, adding that the announcement was out of "extreme precaution."
Florence, which looks to be headed toward the Carolinas is moving to the west-northwest at 13 mph. The governor of South Carolina ordered the state's entire coastline to be evacuated starting at noon Tuesday.
The storm's first effects were already being seen on barrier islands as dangerous rip currents hit beaches and seawater flowed over a state highway. Communities along a stretch of coastline that is vulnerable to rising sea levels due to climate change prepared to evacuate.
For many people, the challenge could be finding a safe refuge: If Florence slows to a crawl just off the coast, it could bring torrential rains to the Appalachian mountains and as far away as West Virginia, causing flash floods, mudslides and other dangerous conditions.
The biggest threat to the DC region from Florence is potentially heavy rains. Current forecast totals for the area now 2 to 8 inches.
FOX 5 Meteorologist Gary McGrady says Florence is 1,200 miles from Wilmington, North Carolina, and the same distance from Ocean City, Maryland.
The storm's potential path also includes half a dozen nuclear power plants, pits holding coal-ash and other industrial waste, and numerous eastern hog farms that store animal waste in massive open-air lagoons.
Florence gained strength in about a day, from a Tropical Storm to a Cat. 1 Hurricane by Sunday evening. This is the second time this storm has reached this level of intensity. It was briefly a category 4 on September 5, before weakening to a tropical storm the next day.
However, Florence is expected to be the strongest in the region since Hurricane Hugo made landfall with 135 mph winds back in September of 1989.
"With forecasts calling for Florence to be packing winds near 140 mph at landfall, it may become the strongest storm on record to hit the Carolinas," says FOX 5 Meteorologist Mike Thomas.
He says the potential for storm surge will be the number one concern with Florence initially for those to the north of where the eye makes landfall.
While the storm's path is still unclear, McGrady says he sees similarities from Florence to Hurricane Fran of 1996, which also made a large impact on the North Carolina coast.
Fran did a lot of damage with wind while turning north through North Carolina in Virginia, eventually bringing over 16 inches of rain in Central Virginia.
"There are a lot of variables from where the greatest rain happens from a tropical system," says McGrady.
National Hurricane Center Director Ken Graham warned that Florence was forecast to linger over the Carolinas once it reaches shore. People living well inland should prepare to lose power and endure flooding and other hazards, he warned.
"It's not just the coast," Graham said. "When you stall a system like this and it moves real slow, some of that rainfall can extend well away from the center."
A warm ocean is the fuel that powers hurricanes, and Florence will be moving over waters where temperatures are peaking near 85 degrees (30 Celsius), hurricane specialist Eric Blake wrote. And with little wind shear to pull the storm apart, Florence's hurricane wind field was expected to expand over the coming days, increasing its storm surge and inland wind threats.
Two other storms are also spinning in the Atlantic. Hurricane Isaac was expected to lose strength as it reaches the Caribbean, and Helene, much farther out to sea, may veer northward into the open ocean as the 2018 hurricane season reaches its peak.
Preparations for Florence were intensifying up and down the densely populated coast of North Carolina. The parking lot has been full for three days at the Ace Hardware store in coastal Calabash, North Carolina, where manager Tom Roberts said he sold 150 gas cans in two hours Monday, along with generators, plywood, rope, manual can openers, sand bags and a plethora of other items.
"I've been doing this since 1983," Roberts said as he completed an order for another 18-wheeler full of supplies. "This is the craziest one."
Many newcomers have moved to the coast in the nearly 19 years since the last strong hurricane -- Floyd -- threatened the area. Roberts said he's telling them to get out of town.
"I'm telling them to go inland, but I'm worried about the rain and tornadoes too," Roberts said.
Several meteorologists said Florence could do what Hurricane Harvey did last year over Texas, dumping days of rain, although not quite as bad.
"I think this is very Harvey-esque," said University of Miami hurricane expert Brian McNoldy. "Normally, a landfalling tropical cyclone just keeps on going inland, gradually dissipating and raining itself out. But on rare occasions, the steering patterns can line up such that a storm slips into a dead zone between troughs and ridges."
On North Carolina's Outer Banks, Dawn Farrow Taylor, 50, was gathering photos and important documents and filling prescriptions Monday before heading inland. She grew up on the island chain, and says this will be only the second time she's evacuated.
"I don't think many of us have ever been through a Category 4. And out here we're so fragile. We're just a strip of land -- we're a barrier island," she said.
In the village of Buxton, Liz Browning Fox plans to ride the storm out in her house on top of a ridge. She believes her home, built in 2009, will be secure, but it's hard to foresee all potential hazards.
"You never know, there could be tree missiles coming from any direction," she said. "There is no way to be completely safe."
In announcing his evacuation order, South Carolina Gov. Henry McMaster said an estimated 1 million people would be fleeing the coast. Eastbound lanes of Interstate 26 heading into Charleston and U.S. 501 heading into Myrtle Beach will be reversed when the order takes effect.
North Carolina Gov. Roy Cooper said his state was "in the bullseye" of the storm and urged people to "get ready now."
The Associated Press contributed to this report.