PORTSMOUTH, Va. (WAVY) — Florence quickly intensified over the Atlantic Ocean on Monday, becoming a dangerous Category 4 hurricane.
In a Monday night update, the National Hurricane Center said Florence maintained its strength as a Category 4 hurricane with 140 mph winds — picking up 10 mph since noon Monday.
The hurricane center on Tuesday issued hurricane and storm surge watches for parts of the region, including North Carolina’s Outer Banks.
Virginia Gov. Ralph Northam announced Monday afternoon that all residents in Zone A — the lowest-lying, most flood-prone areas of the Tidewater region — must evacuate. The evacuation goes into effect at 8 a.m. Tuesday.
In North Carolina, Dare County issued a state of emergency Monday as well as evacuation orders for all residents and visitors. Evacuations began Monday at noon on Hatteras Island, and continue 7 a.m. Tuesday for the rest of the county.
Currituck County officials issued an evacuation order for all visitors in the area of Corolla and Carova.
Hyde County declared a state emergency as well — and issued a mandatory evacuation for visitors on Ocracoke Island that went into effect at noon on Monday.
On Monday, the storm was 1,240 miles east-southeast of Cape Fear, North Carolina, and was tracking west at 13 mph. Over the next couple of days, Florence’s movement is forecast to shift to the west-northwest with increasing speed.
The hurricane center said Florence will move between Bermuda and the Bahamas on Tuesday and Wednesday — and then approach the coast of South Carolina or North Carolina on Thursday.
Florence is expected to be a dangerous Category 4 hurricane by that time.
The first effects of what forecasters are already calling a large and extremely dangerous hurricane were already being seen on barrier islands Monday as dangerous rip currents and seawater flowed over the state highway. People were told to prepare to evacuate communities up and down a stretch of coastline already identified as particularly vulnerable to rising sea levels due to climate change.
For many, the challenge could be finding a safe refuge: If Florence slows to a crawl just off the coast, it could carry torrential rains up into the Appalachian mountains, causing flash floods, mudslides and other dangerous weather across a wide area.
Exactly where Florence makes landfall remains unclear.
The cone of uncertainty for Florence stretched from Charleston, South Carolina, to Hatteras early Monday. Regardless of where Florence hits, the Hampton Roads region is expected to feel the rain, storm surge and wind effects.
States of emergency were declared by the governors of Virginia, North Carolina and South Carolina. Cities across Hampton Roads began notifying residents of a pre-hurricane preparations over the weekend.
Related: Local emergency declarations
National Hurricane Center Director Ken Graham warned that Florence was forecast to slow down significantly and linger over the Carolinas once it reaches shore, dropping heavy rainfall as far as West Virginia. People living well inland should prepare to lose power and anticipate 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 along with life-threatening freshwater flooding.
Preparations for Florence were intensifying up and down the densely populated coast. Since reliable record-keeping began more than 150 years ago, North Carolina has only been hit by one Category 4 hurricane: Hazel, with 130 mph winds in 1954.
Several meteorologists said Florence could do what Hurricane Harvey did 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.”
10 On Your Side will continue to follow Florence and its potential impact on air and online, but now is the time to prepare.