The center also said that Hurricane Isaac has become the 5th named hurricane of the 2018 Atlantic season.
"To the incredible citizens of North Carolina, South Carolina and the entire East Coast - the storm looks very bad!"
"While our state is not under any current weather advisories, in Florida, we know how quickly a major storm can shift its path and we cannot leave preparedness up to chance".
Where is the hurricane now?
At 11 a.m. EDT, the hurricane center said Florence's maximum sustained winds were estimated to be 75 miles per hour.
According to the U.S. National Hurricane Center, Florence rapidly strengthened into a "major" hurricane early Monday morning that will likely bring a "life-threatening" storm surge along portions of the East Coast.
The NHC issued a warning Monday morning, explaining when powerful gusts may approach. Wherever it lands, it won't move much for three or four days, creating a storm surge and wind event, Osterberg said.
What else should I know?
Poor putting costs Tiger Woods on day two at BMW
The younger brother of US Open and PGA Championship victor Brooks Koepka also had a double bogey on the par-3 16th. He was at 9 under when Woods finished, only to make consecutive bogeys and finish with a two-putt birdie for a 62.
"While it is too soon to determine the exact timing, location, and magnitude of these impacts, interests at the coast and inland from SC 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".
South Carolina Gov. Henry McMaster also suspended his campaign and asked President Donald Trump for a federal emergency declaration.
"We here in North Carolina are bracing for a hard hit", Cooper said during a press conference outlining the state's preparations.
Forecasters say that storm was about 1230 miles (1985 kilometers) east of the Windward Islands with maximum sustained winds of 75 mph (120 kmh).
Florence is now moving west at around 13 miles per hour (20 kph), and is forecast to drench a large swath of the US East Coast running from northern Florida to New Jersey.
All of Hatteras Island was under mandatory evacuation order and other parts of the Outer Banks will have to evacuate by 7 a.m. EDT (1100 GMT) on Tuesday, Dare County Emergency Management said in a statement.
Florence was producing large swells expected to reach from the northern Caribbean to the southern coasts of Canada's Maritime provinces.
"Florence is expected to be an extremely unsafe major hurricane through Thursday (Sept. 13)", said officials.
In addition, in the Pacific, what's now Hurricane Olivia is forecast to approach Hawaii as a tropical storm on Tuesday.