Even as its top winds dipped to 130 miles per hour, Hurricane Florence remained a Category 4 storm on Tuesday and was expected to approach Category 5 status, the most damaging, as it moves toward the coast of North and South Carolina.
The center of the massive storm is forecast to meander Thursday, Friday, and Saturday over the Carolinas’ coastline, with North Carolina likely to receive the brunt of the initial impact, according to Tuesday’s projections from the National Hurricane Center.
However, weather officials are warning that the hurricane’s size is “staggering”: ‘‘We could cover several states easily with the cloud cover alone,’’ National Hurricane Center Director Ken Graham warned. ‘‘This is not just a coastal event.’’
(In the following map, “M” stands for “major hurricane” with wind speeds greater than 110 miles per hour; “H” stands for “hurricane” with wind speeds between 74 and 110 miles per hour; and “D” stands for “tropical depression,” with wind speeds of less than 39 miles per hour.)
North Carolina Governor Roy Cooper said his state is ‘‘in the bullseye’’ and urged people to ‘‘get ready now.’’ Meanwhile, South Carolina’s governor ordered the state’s entire coastline evacuated starting at noon Tuesday, and coastal evacuations were also in effect for Virginia and North Carolina.
The earliest reasonable time that tropical storm force winds could arrive on the East Coast is late Wednesday, and the most likely time is Thursday morning.
“Wednesday should be the last full day to prepare, so plan accordingly,” the National Hurricane Center said on Twitter.
North Carolina, again, seems to be the state that could bear the brunt of the winds, along with South Carolina and parts of southern Virginia. Georgia, West Virginia, Maryland, the District of Columbia, Delaware, New Jersey, southern Pennsylvania, and eastern Tennessee, Kentucky, and Ohio could also see strong winds.
The forecasters also expect that there will be a 90 percent chance of winds at 58 miles per hour for parts of the storm.
“Florence is likely to cause damaging hurricane-force winds along parts of the coasts of South & North Carolina,” the center wrote on Twitter. “Damaging winds could also spread well inland into portions of the Carolinas & Virginia.”
A hurricane watch was also in effect Tuesday for Edisto Beach, S.C., to Virginia’s southern border, with the first hurricane-force winds arriving late Thursday.
Forecasters said Tuesday that Florence could reach Category 5 status as it slows and strengthens over very warm ocean water off the coast of North and South Carolina.
By 8 a.m. Tuesday, Florence’s eye was about 950 miles east-southeast of Cape Fear, North Carolina, and moving west-northwest at 15 miles per hour. It was moving between Bermuda and the Bahamas on Tuesday and was expected to approach the Carolinas on Thursday.
The storm is also expected to trigger “life-threatening, catastrophic flash flooding & significant river flooding over portions of the Carolinas and Mid-Atlantic states from late this week into early next week,” forecasters wrote on Twitter.
Seven-day rainfall totals are forecast to reach 10 to 20 inches over much of North Carolina and Virginia, and even 30 inches in some places.
‘‘This is going to produce heavy rainfall, and it may not move very fast,” said Craig Fugate, former director of the Federal Emergency Management Agency. “The threat will be inland, so I’m afraid, based on my experience at FEMA, that the public is probably not as prepared as everybody would like.’’
Combined with high tides, the storm surge could swell as high as 12 feet, forecasters said.
“Florence is likely to produce a life-threatening storm surge along the coastlines of South Carolina, North Carolina & Virginia, and a Storm Surge Watch is in effect for a portion of this area,” meteorologists said on Twitter.
‘‘The water could overtake some of these barrier islands and keep on going. With time, the wind pushes the water into every nook and cranny you can think of,’’ Graham said. ‘‘All you have to do is look up at your ceiling, and think about 12 feet [of water]. That, folks, is extremely life-threatening.’’
(Forecasters advised that regardless of what the following map shows, residents should always follow evacuation orders from local officials.)
A warm ocean gives hurricanes their fuel, and Florence is moving over an area with water temperatures nearing 85 degrees, hurricane specialist Eric Blake wrote. With little wind shear to pull the storm apart, hurricane-strength winds have been expanding to 40 miles from the eye of the storm, and tropical-storm-force winds 150 miles from the center. Information gathered Tuesday by a hurricane-hunting aircraft suggests it will intensify again as it nears the coast, approaching the 157-mile-per-hour threshold for a worst-case Category 5 scenario.
This story has been updated as of Tuesday afternoon.Material from the Associated Press was used in this report.