A Category 4 hurricane with 130 mph winds is bearing down on the US East Coast, bringing a risk of devastating floods.
Hurricane Florence is expected to make landfall somewhere between North Carolina, South Carolina, and the Mid-Atlantic states on Thursday evening or Friday morning, according to the National Hurricane Center (NHC).
The hurricane could remain powerful as it passes over the US mainland, the NHC warned on Monday morning.
The hurricane is set to inundate low-lying islands off the coast of North Carolina, like the Outer Banks and other barrier islands, according to the NHC's "cone of probability" forecast. Heavy rain may impact as far inland as Charlotte, North Carolina's largest city, though the severity will depend on the storm's track, according to The Charlotte Observer.
Evacuations now extend to 1 million people in South Carolina — Governor Henry McMaster ordered the state's entire 187-mile coastline evacuated by Tuesday afternoon, reports The Post and Courier.
"Pretend, assume, presume that a major hurricane is going to hit right smack dab in the middle of South Carolina and is going to go way inshore," McMaster said in a press conference.
Evacuation orders are mounting
Some South Carolina schools and most offices have been closed in Charleston, the largest city in South Carolina, in advance of the storm, reports The Post and Courier. The famed vacation destination of Hilton Head, South Carolina is also in the storm's likely path.
In North Carolina, evacuations have been ordered in Dare County, which includes the Outer Banks and Hatteras, a popular vacation spot, as well as other coastal counties, according to The Richmond Times-Dispatch.
"Everyone in Dare County is encouraged to evacuate as soon as possible regardless of the established time frames," the Dare County Emergency Management said on Monday.
North Carolina Governor Roy Cooper said at a press conference that the state is in the "bullseye" of the hurricane, according to The Raleigh News and Observer.
The latest Florence forecast
Predicting hurricane tracks is a difficult science, and the NHC said there are still uncertainties about the storm's track. So it may shift over the coming days, but if predictions hold, Florence is set to be the first Category 4 hurricane to make landfall in North Carolina since Hurricane Hugo tore through the state in 1989.
"There is an increasing risk of two life-threatening impacts from Florence: storm surge at the coast, freshwater flooding from a prolonged and exceptionally heavy rainfall event inland, and damaging hurricane-force winds," the NHC warned.
Florence is a Category 4 storm, which means it has wind speeds between 130-156 mph. Its center is located about 580 miles southeast of Bermuda. The NHC expects the hurricane's winds to strengthen as it moves west by Tuesday, drawing energy from the warm water. The storm is moving west at 30 mph.
The chart below shows the probability of the area that will experience at least 39 mph winds. The area in purple corresponds to a 90% or higher probability of experiencing those gusts:
The NHC also said that the storm's effects, including rain, high wind, rip currents, and tidal surges will likely be felt outside of the "cone of probability" and could extend hundreds of miles from the storm's center.
Heavy rains are expected
Beyond the damage from wind and high surf, Hurricane Florence is predicted to slow over the Carolinas, where it may dump up to 30 inches of rain over much of North and South Carolina, reports The Washington Post.
Sluggish or stalled hurricanes — like Hurricane Harvey that flooded swaths of Houston, Texas and the Gulf Coast last year — can become even more dangerous as they stick around, pouring rain.
These types of slow-moving hurricanes are becoming more frequent: recent research from the National Oceanic and Atmospheric Administration found that storms slowed by an average of 10% over land between 1949 and 2016. Over that same time period, the average global temperature rose 0.5 degrees Celsius. (Warmer air can hold more moisture, which allows slower storms to produce heavier rainfall.)
Residents of South Carolina and North Carolina's low-lying barrier islands are preparing for the storm's onslaught.
"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. ... Already we're getting some overwash, the ocean is coming over 12," Dawn Farrow Taylor, a resident of North Carolina's Outer Banks, told the Associated Press.
Hurricane troubles may not end with Florence. Hurricane Isaac, which churning in the mid-Atlantic, has wind speeds of over 75 mph as of Monday morning, though the NHC expects Isaac to weaken as it approaches the Caribbean. Behind Isaac, Hurricane Helene is rapidly gaining strength, with wind speeds of over 105 mph. Helene is moving in a west-northwest direction at 16 mph.
Meanwhile in the Pacific Ocean, Hurricane Olivia is heading towards Hawaii. The storm is predicted to hit the Hawaiian Islands on Wednesday morning, according to the NHC.
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