The governor of SC on Sept. 10 said that mandatory evacuations will start at Tuesday, Sept. 11 at 12 p.m. local time.
"We know this evacuation order I'm issuing is going to be inconvenient", McMaster said of the decision, which affects over 1m residents. He added that the disruption was worth the effort to save lives.
That's not all from Holthaus: "As much as 48 inches of rain could fall", he tweeted.
Historically, 90 per cent of fatalities from hurricanes, tropical storms and tropical depressions have been caused by water, NHC spokesman Dennis Feltgen said. The confidence in a North Carolina landfall Thursday night is growing, but there's still room for improvement regarding model disagreement.
During his press conference Monday, McMaster appeared open to the possibility of modifying his evacuation plan.
On Monday afternoon, Donald Trump cancelled a scheduled appearance for Friday in Jackson, Mississippi. The wind field is expected to keep growing, which will increase the storm surge and inland wind threats, the service said in a statement.
Duke Energy is already projecting widespread power outages in the Carolinas that could take days to weeks to restore, spokeswoman Grace Rountree said.
If it reaches the feared category four status, it would be the biggest hurricane in the United States since Hurricane Harvey in 2017. That storm brought $125bn in damage last summer, mostly in Texas. Hurricane Florence has been upgraded to a major category 4 hurricane as of noon on Monday.
American is waiving its change fees - which can cost US$200 or more - for customers ticketed to fly to 23 airports in Georgia, Virginia and the Carolinas.
The storm's first effects were already being seen on barrier islands as risky rip currents hit beaches and seawater flowed over a state highway.
"This is a very risky hurricane", McMaster said, adding that the evacuation order for coastal counties was "mandatory, not voluntary".
"If the track were to shift more westward, that would put Charlotte at more risk for both wind and flooding", he said, possibly including heavy rain in the headwaters of the Catawba River, which flows toward Charlotte. It was centered about 1,230 miles east-southeast of Cape Fear, North Carolina, and moving west at 13 mph.
Large swells are already affecting Bermuda and parts of the U.S. East Coast, according to the NHC.
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".