(CBS) — Tropical Storm Florence turned into a hurricane Sunday morning and swirled toward the U.S. for what forecasters said could be a direct hit on the Southeast toward the end of the week.

The storm’s sustained winds reached 75 mph, just over the threshold for a hurricane, as it made its way across the Atlantic, about 750 miles southeast of Bermuda, the National Hurricane Center said. It was moving west at 6 mph.

The Miami-based center said that it was still too early to predict the hurricane’s exact path but that a huge coastal area from northern Florida to North Carolina should prepare for a major hit.

“Florence is forecast to rapidly strengthen to a major hurricane by Monday, and is expected to remain an extremely dangerous major hurricane through Thursday,” the NHC said in an 11 a.m. advisory on Sunday.

The hurricane center said Florence will likely be a Category 4 storm as it moves across the Atlantic. A Category 4 hurricane packs winds of 130 mph or more and has the potential for catastrophic damage.

The governors of North and South Carolina and Virginia declared states of emergency to give them time to prepare, and the Navy said ships in Virginia’s Hampton Roads area would leave port for their own safety.

 

cr490 weather graphic 90918 frame 0 Florence Strengthens To Become A Hurricane

This map shows the projected path of Hurricane Florence on Sunday, Sept. 9, 2018. CBS NEWS

North Carolina Gov. Roy Cooper said in a statement Sunday that coastal and inland residents alike need to get ready for potentially heavy rainfall and flooding from the storm. Cooper urged residents to “review your emergency plans and gather your supplies now.”

In a news conference Sunday, South Carolina Gov. Henry McMaster urged residents to begin making preparations before the storm hits. “Pretend, presume and assume that a major hurricane is going to hit smack dab in the middle of South Carolina,” he said.

There has not been a decision on evacuations, McMaster said.

The storm brings an increasing risk of two life-threatening impacts: storm surge along the coast and freshwater flooding from prolonged rains, the hurricane center said.

Dangerous swells generated by Florence affected Bermuda and have begun to reach parts of the Eastern Seaboard.

The National Weather Center warned of dangerous rip currents in popular tourist areas like Virginia Beach and the Outer Banks.

Advisories warning of dangerous beach conditions or coastal flooding were in effect for parts of New Jersey, Delaware, Virginia, North Carolina, South Carolina, Georgia, and Florida.

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