Eastern time. It has picked up speed and is now moving west-northwest at 9 miles per hour.
Grocery stores are restocking shelves with water and bread, and supply stores are selling a lot of plywood and generators Monday as East Coast communities prepare for Hurricane Florence to strike hard later this week.
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.
Several meteorologists said Florence could do what Hurricane Harvey did a year ago over Texas, dumping days of rain, although not quite as bad.
"We're not going to gamble with the lives of the people of SC", the state's governor, Henry McMaster, said in an afternoon press briefing Monday as he announced that eight counties along the state's 187-mile coastline would begin to evacuate on Tuesday.
Florence is now forecast to approach the North Carolina or SC coast by Thursday, although tropical storm-force winds from the system could reach the coast as early as Wednesday.
A spokeswoman for the Ministry of National Security said: The ministry is reminding that all public services, including government offices, public transport and public schools will be open and operational.
"None of the guidance suggest that Florence has peaked in intensity", the Hurricane Center said, predicting that its peak winds will reach 155 miles per hour Tuesday, just 2 miles per hour shy of Category 5.
Hurricane Helene, was spinning in the Atlantic off West Africa's Cabo Verde Islands with 85-mph (140-kph) winds on Sunday, but did not appear to pose an immediate threat to land.
It will move between Bermuda and the Bahamas Tuesday and Wednesday, and approach the eastern US coast on Thursday.
By Tuesday night, it is projected to be almost a Category 5 storm with winds near 150 miles per hour.
Not only has the storm exploded in intensity, but its zone of hurricane-force winds approximately doubled in size Monday.
SC emergency officials have elevated the state's readiness again, as they prepare for the possibility of Florence becoming a major hurricane and affecting the state.
Swells generated by Florence are affecting Bermuda and are beginning to reach portions of the US East Coast.
The governors of SC and Virginia declared states of emergency on Saturday. The state's emergency management agency said it is "preparing for the possibility of a large-scale disaster".
"It is against the law to charge an excessive price during a state of emergency".
As a precaution against Florence, South Carolina Governor Henry McMaster ordered an estimated 1 million coastal residents in his state to move inland. The statute will remain in effect until the state of emergency is lifted. Roberts said he's telling them to get out of town.
"Our best defense is good preparation", Cooper said as he urged residents to plan evacuation routes, clear their yards of debris that could cause damage in high winds, and discuss how they would contact family and friends.
Florence could nearly double that price tag with total losses reaching $27 billion, said Chuck Watson, a disaster modeler with Enki Research in Savannah, Georgia.
Crystal Kirwan and her family were preparing to leave their home in Moyock, North Carolina on Monday. "We live paycheck to paycheck, being a military family, and it's four days until payday".
To reiterate the forecast for central Georgia, direct impacts are not expected at this point other than breezy conditions for late week.
Meanwhile, crowds formed at supermarkets starting Sunday as people tried to stock up on supplies.
In coastal Charleston, South Carolina, city officials offered sandbags to residents.
"I don't think many of us have ever been through a Category 4".
Rapidly intensifying Hurricane Florence could strike a direct and unsafe blow anywhere from the Carolinas to the Mid-Atlantic region later this week.
The hurricane became a Category 4 storm about noon Monday.
Stay with 10News throughout the Atlantic hurricane season.
The Atlantic hurricane season has picked up in earnest: There are three tropical systems worth tracking across the Atlantic. Drawing energy from the warm water, the now Category 2 storm could be a fearsome Category 4 with winds of 130 miles per hour (209 kph) or more by Tuesday.
CNN meteorologist Gene Norman compared the conditions to boiling water on a stove, with the water taking a while to react to an increase and then decrease in the temperature of the element beneath it.
"The storm is strong and getting stronger", Cooper said.