Hurricane Florence Intensifies Into Category 4 Storm As It Barrels Toward US East Coast

Hurricane Florence Intensifies Into Category 4 Storm As It Barrels Toward US East Coast

"Further strengthening is anticipated, and Florence is expected to be an extremely dangerous major hurricane through Thursday," the NHC said in a statement.

The center of the hurricane is forecast to move across the Atlantic Ocean between Bermuda and the Bahamas tomorrow and Wednesday (Sept. 11–12), before approaching the coast of South Carolina or North Carolina on Thursday. [Hurricane Season 2018: How Long It Lasts and What to Expect]

The governors of both states, North and South Carolina, issued mandatory evacuations of coastal areas today (Sept. 10), according to CNN.

Large swells are already affecting Bermuda and parts of the U.S. East Coast, according to the NHC. Such swells can lead to dangerous surf and rip currents, the NHC warned.

Major hurricane status refers to hurricanes with sustained winds of at least 111 mph (178 km/h) — labeled Category 3 or higher. 

Warm sea surface temperatures and low wind shear (which, when high, can zap the energy from a storm) have set up perfect conditions for Florence to intensify. "These conditions are expected to lead to significant strengthening during the next 12 to 24 hours, and Florence is forecast to be a very powerful major hurricane on its approach to the southeastern United States," the NHC said in a statement this morning.

Though the NHC can't pinpoint with certainty the exact location and magnitude of the impacts, they said, "interests at the coast and inland from South Carolina into the mid-Atlantic region should closely monitor the progress of Florence, ensure they have their hurricane plan in place, and follow any advice given by local officials."

Over the weekend, the governors of Virginia, North Carolina and South Carolina declared states of emergency, according to CNN.

"We are preparing for the worst, and of course hoping for the best," South Carolina Gov. Henry McMaster said, as reported by CNN.