The latest projection for the path of the storm, released Sunday, shows the storm track centered on Wilmington, N.C., with forecasters predicting it will be a "dangerous major hurricane" by the time it reaches the coast later in the week.
The turbulent storm was last spotted 710 miles southeast of Bermuda moving west at 6mph. There is at least a five percent chance of tropical storm-force winds in Northeast Florida, though the storm is predicted to track farther north.
A Caribbean white sand beach it was not, but passengers appeared to be making the best of it.
"The risk of other direct impacts associated with Florence along the US East Coast next week has increased".
None of the storms now presents an immediate threat to South Florida, according to the 5 p.m. Sunday advisory from the National Hurricane Center. South Carolina Gov. Henry McMaster emphasized that there's no way to know yet when and where the storm will hit land, or when evacuations might be called.
The Miami-based center said late Sunday that Isaac was about 1305 miles (2100 kilometers) east of the Windward Islands with maximum sustained winds of 75 mph (120 kmh). Florence will likely become a major hurricane Monday night, and will remain a strong, risky hurricane through next week as it approaches the east coast.More news: Serena fined $17K after US Open Final
US residents from SC to Virginia were warned that Florence posed an increasing risk of life-threatening coastal storm surge, as well as flooding from heavy rainfall inland.
At 11 a.m. EDT, the Miami-based hurricane center said Florence's maximum sustained winds were estimated to be 65 miles per hour (100 kph).
Hurricane Isaac is the fifth hurricane of the 2018 Atlantic season.
Hurricane Florence is around 500m north of the Leeward Islands, which includes four Commonwealth nations - Saint Kitts, Nevis, Barbuda and Antigua. And it's not likely to weaken before reaching the shores of North and SC and Virginia on Thursday, AccuWeather meteorologist Brett Rossi said.
"Pretend, assume, presume that a major hurricane is going to hit right smack dab in the middle of SC and is going to go way inshore", McMaster said.
Meteorologists are also tracking two tropical storms which formed off the coast of Africa.