Many newcomers have moved to the coast in the almost 19 years since the last strong hurricane - Floyd - threatened the area.
While Isaac is forecast to begin weakening by Tuesday as it approaches the Lesser Antilles, it is still expected to be at or near hurricane intensity when it reaches the islands, and the uncertainty in the intensity forecast is higher than usual.
He said as far as the National Emergency Planning Organisation is concerned "we are taking no chances and we are leaving no stone unturned in respect to the preparation of the state, the country and its citizens for this incoming weather system".
Helene is a Category 2 hurricane that's blowing winds between 96-110 miles per hour.
On North Carolina's Outer Banks, Dawn Farrow Taylor, 50, was gathering photos and important documents and filling prescriptions Monday before heading inland.
The parking lot has been full for three days at the Ace Hardware store in coastal Calabash, North Carolina, where manager Tom Roberts said he sold 150 gas cans in two hours Monday, along with generators, plywood, rope, manual can openers, sand bags and a plethora of other items. Both North and SC have declared states of emergency in preparation.
In coastal Charleston, South Carolina, city officials offered sandbags to residents.
Myrtle Beach hardware stores and supermarkets were busy ringing up sales of bottled water, plywood and generators.
The storm is now around 400 miles south of Bermuda and is moving at 16 mph (26 kph).
North Carolina crews were getting bulldozers and chain saws ready.
At 03:00 GMT Issac was about 2 100km east of the Windward Islands - a region still recovering from last year's powerful Hurricane Maria - with winds of 120km/h.
We'll just have to wait and see where all of them go.
The US navy has ordered ships at its major base in Hampton Roads, Virginia, base to put to sea, saying "the forecasted destructive winds and tidal surge are too great to keep the ships in port".
The center of Hurricane Helene was located near latitude 16.0 North, longitude 33.6 West. Helene is moving toward the west-northwest near 14 miles per hour (22 km/h), and this motion is expected to continue with a decrease in forward speed through tonight.