Tropical Storm Florence, now about 765 miles from Bermuda and 1,500 miles from the East Coast, is expected to regain strength and return to hurricane status later in the day Sunday.
Helene has sustained winds of 45 miles per hour and is moving west at 13 miles per hour.
According to WRAL meteorologist Mike Moss, although Florence is already creating rip currents along North Carolina's coast, the storm could have direct impacts on as far south as Georgia or as far north as Virginia by Thursday or Friday. As Florence's path moves closer to the USA coastline in the next week Florence is expected to regain category three hurricane status tonight.
By 5 p.m. Monday, Florence was centered about 1,170 miles (1,880 kilometers) east-southeast of Cape Fear, North Carolina, and moving west at 13 mph (20 kph).
In announcing his evacuation order, South Carolina Gov. Henry McMaster said an estimated 1 million people would be fleeing the coast.More news: Kulsoom Nawaz Just Passed Away After Her Battle With Cancer
Even if Florence avoids a direct hit on the East Coast, it will likely come very close, resulting in risky surf, beach erosion, and the potential for coastal flooding.
Forecasters said it is too early to know the exact path the storm will take but warned that it could roll ashore in the Carolinas by Thursday.
Historically, 90 percent of fatalities from hurricanes, tropical storms and tropical depressions have been caused by water, NHC spokesman Dennis Feltgen said. This system will likely become a tropical storm today and a hurricane Sunday or Monday.
On Friday, North Carolina declared a state of emergency.
Florence, the sixth tropical storm in the Atlantic basin this year, intensified into a hurricane on Sunday and will rapidly gain force as it churns over the open ocean toward the US East Coast, with landfall likely in the Carolinas later this week, forecasters said.More news: Defeat gives England and Southgate a reality check
"Those are the benchmark storms on the Carolina coastline, strong Category 4 hurricanes, but the difference with this is it's not going to move fast".
Florence is expected to become a major hurricane by Monday, the National Hurricane Center said, adding that "a significant phase of intensification" is expected late Saturday. Hugo in 1989 was the one before that and was a Category 4 at landfall.
The hurricane center says "catastrophic" Category 4 storms generate sustained winds of at least 130 miles per hour. Strengthening into a tropical storm is forecast this weekend and possibly a hurricane early next week as it approaches the Lesser Antilles.
The category 1 hurricane was mustering might as it traveled over warm Atlantic waters, about 625 miles southeast of Bermuda at 5.am.
A westward motion is forecast to continue through the end of the week, with Isaac expected to move across the Lesser Antilles and into the eastern Caribbean Sea Wednesday night or Thursday. According to an update on the storm, it is becoming "better organized".More news: Botham Jean's killer confirmed as Amber Guyger