Florence has restrengthened to a Category 4 hurricane according to a National Hurricane Center tweet with winds of 130 mph. The storm is moving to the west at 11 mph.
Monday morning, Jeff Orrock, lead forecaster at the National Weather Service's Wakefield office, said the region needs to brace for the storm and residents need to have a plan in place.
"It's all a matter of severity," said Orrock. "There pretty much are two schools of thought right now. One scenario has it coming into the Wilmington, N.C., area and moving fast. In that case, we probably get tropical storm-force winds and rain up to 8 inches."
In the other, worse, scenario, the storm makes landfall between Cape Lookout and Hatteras and stalls as it moves inland.
"We could see astronomical flooding if that happens," Orrock said. "We could see flooding in places where we've never seen flooding before."
As of 5 a.m. EDT, Florence was centered about 625 miles (1,005 kilometers) southeast of Bermuda, moving west at 9 mph (15 kph). Its maximum sustained winds are at 105 mph (165 kph). Drawing energy from the warm water, it could have top sustained winds of 130 mph (209 kph) or more by Tuesday, the Miami-based center said.
The mid-Atlantic coast is already seeing the effects of Florence, which is pushing storm surge ahead of its path. Dangerous surf and rip currents already are being reported along the coast from northern Florida to Long Island, N.Y. Conditions are expected to deteriorate as the week progresses.
Flooding already is being reported during high tide in regional areas prone to high water because of pull from the new moon.
"And the water is going to stay high for the rest of the week, and that's before the storm," said Skip Stiles of Wetlands Watch. "The ground is already saturated and with this moon tide and wind pushing more water in, this could really be something. If it stalls and we get lots of rain, and with the tide stopping all the outflow, we could see lots of flooding."
Officials in Hampton Roads cities and counties in northeastern North Carolina are preparing for potential evacuation orders.
The hurricane center also said that Hurricane Isaac, much farther out to sea, has become the 5th named hurricane of the 2018 Atlantic season, joining Helene as the third currently active storm.
It's too early to know the exact path, but forecasters said Florence could blow ashore in the mid-Carolinas by Thursday.
Up and down the densely populated coast, residents have been told to prepare, and not just for a possible direct blow. Florence could slow or stall on or near shore, scooping up massive amounts of seawater. Some forecasting models show it could unload a foot or two of rain in places, causing devastating inland flooding. Forecasters also warned of a rising threat of life-threatening storm surge, along with the damaging winds.
The governors of North and South Carolina, and Virginia, declared states of emergency far ahead of the approaching storm.
Navy ships off Virginia's coast were preparing to sail out of the path.
Naval Station Norfolk employees were told not to leave their vehicles at the sprawling base later this week because of the flood threat. The Navy planned to send ships from the Hampton Roads area of Virginia out to sea.
Lining up behind Florence, Isaac was about 1,230 miles (1,985 kilometers) east of the Windward Islands with top winds of 75 mph (120 kph) early Monday, moving west at 13 mph (20 kph). It should accelerate over the next 36 hours and is forecast to head into the Caribbean Sea. Helene was in line behind Isaac with winds of 85 mph. It is expected to eventually move to the north-northwest, where it will not pose a threat to land.