Hurricane Florence is threatening to strike the East Coast on Friday as a Category 5 hurricane, prompting evacuations in the Carolinas and an emergency declaration in Maryland ahead of potentially “historic” flooding.
As the storm makes landfall in the Southeast, potentially with winds of 150 mph, Florence is expected to stall, potentially battering beaches for hours and dropping a foot of rain or more across an already waterlogged part of the country. Heavy rain is expected to stretch into the mid-Atlantic through the weekend.
Even as the precise forecast remained unclear, meteorologists and elected officials warned residents to prepare for heavy rain and flooding, at least.
“At this time there’s still some uncertainty about the track of the storm and its potential impact,” said Gov. Larry Hogan as he announced a state of emergency Monday afternoon. “But we are preparing for the potential of historic, catastrophic and life-threatening flooding.”
As of midday Tuesday, Florence was within 900 miles and 72 hours away from an expected blow to the North Carolina coast, though National Hurricane Center forecasters noted that its landfall estimate could be off by 100 or 150 miles based on average errors in forecasts so far in advance.
They said dangers “will extend well away from the center” of the storm, and urged residents up and down the coast to prepare.
“All interests from South Carolina into the mid-Atlantic region should ensure they have their hurricane plan in place and follow any advice given by local officials,” the hurricane center said in a Monday evening update.
Hurricane and storm surge watches were posted Tuesday from Charleston, S.C., to the Virginia/North Carolina border.
Florence’s maximum sustained wind speeds reached 140 mph late Monday, and meteorologists said the storm’s strength had not yet peaked. Winds weakened slightly to 130 mph early Tuesday, but the cyclone was forecast to strengthen later in the day — “to near category 5 strength within the next 24 to 36 hours,” the hurricane center said at 11 a.m. Tuesday.
It was moving westward into an area with 85-degree waters and little wind shear, when wind speeds and directions vary by altitude and can rip tropical cyclones apart. The hurricane center said the storm’s winds could reach 150 mph, with gusts up to 185 mph, as it approaches the coast. Category 5 storms have sustained winds of at least 156 mph.
“The bottom line is that there is high confidence that Florence will be a large and extremely dangerous hurricane, regardless of its exact intensity,” they wrote.
Hogan’s emergency declaration means the state is beginning to assemble the personnel and equipment that could be necessary amid major flooding. That includes staff for emergency operations centers around the state, swift water rescue boats and flat-bottomed boats, and space in shelters, said Russell Strickland, executive director of the Maryland Emergency Management Agency.
Hogan also put the Maryland National Guard on notice that it may be needed.
“We could have the potential of having historical kind of flooding,” Strickland said. “We’re pretty confident we’re going to have a lot of rain.”
Maryland could begin to feel Florence’s effects by late Thursday, but its precise impacts on the state remained unclear Monday.
The latest forecast cone suggests Maryland could miss the brunt of the storm but still see significant rainfall, possible flooding and tropical storm-force winds. But the forecast is likely to change and shift in the coming days.
Meanwhile, preparations for life-threatening storm surge, winds and flooding already were underway in the Carolinas. Mandatory evacuation orders were issued along the coasts of both North and South Carolina. The governors of those states, plus Virginia, made emergency declarations over the weekend.
South Carolina's governor ordered the state's entire coastline evacuated starting at noon Tuesday and predicted that 1 million people would flee as highways reverse directions. Virginia's governor ordered a mandatory evacuation for some residents of low-lying coastal areas, while some coastal counties in North Carolina have done the same.
North Carolina Gov. Roy Cooper said his state is "in the bullseye" and urged people to "get ready now."
The University of North Carolina at Wilmington, near the shore, canceled its upcoming alumni weekend and all classes starting at noon Monday, encouraging its students to leave campus for safer locations.
In southeast Virginia, the Navy planned to send ships from its Norfolk-area bases out to sea. Naval Station Norfolk told people not to leave their vehicles at the sprawling base later this week because of the flood threat.
It has been decades since the Southeast has faced such a strong hurricane. 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. It has been nearly 19 years since the last strong hurricane, Floyd, threatened the area.
Florida-based Carnival Cruise Line was re-routing its cruise ships, some of which departed from Baltimore, but there were other hurricanes to contend with. There are three active hurricanes in the Atlantic for the 11th time since 1893, and just the second time since 2010, said Philip Klotzbach, a hurricane meteorologist at Colorado State University.
Lining up behind Florence, Isaac was about 900 miles east of the Windward Islands with top winds of 70 mph early Tuesday, accelerating on a path to cross into the lower Caribbean Thursday as a weak hurricane or a tropical storm.
Helene, meanwhile, was still in the Atlantic's spawning ground for hurricanes off the coast of Africa, swirling with 110 mph winds and forecast to become a major hurricane, about 600 miles west of the Cape Verde islands.
The Associated Press contributed to this article.