Hurricane Michael has been upgraded to an “extremely dangerous” category four storm, hours before it is due to make landfall in Florida.
The storm has sustained winds of 145mph (230km/h) and is due to make landfall at about midday (16:00 GMT).
More than 370,000 people in Florida have been ordered to evacuate and move to higher ground.
At least 13 people reportedly died in Central America over the weekend as a result of storm rains and floods.
According to the Associated Press, six people were killed in Honduras, four in Nicaragua and three in El Salvador.
Florida has declared a state of emergency, as have Alabama and Georgia.
The Miami-based National Hurricane Center (NHC) said Michael has remained to be “an extremely dangerous” hurricane.
It warned of a life-threatening storm surge, hurricane force winds and heavy rainfall along the north-eastern Gulf coast.
Michael, it added, could see some additional strengthening before it made landfall in the Florida Panhandle – a strip of land bordering the Gulf of Mexico – or the Big Bend area to its east.
At 07:00 local time on Wednesday, the eye of Michael was about 90 miles (105km) south-west of Panama City, Florida.
The NHC warns that some regions of Florida may experience storm surges of up to 14ft (4m).
And “life-threatening” flash floods may occur as a result of up to 12in (30cm) of rain.
Michael is currently moving northwards at 13mph.
Leaders warns of a ‘monstrous storm’
Weather forecasters, who have said storm surge could reach 12 feet in some areas, have issued a storm surge warning for the stretch between the border of Okaloosa and Walton Counties to the Anclote River.
A storm surge watch is in effect on both sides of the warning area: from the Okaloosa and Walton county line westward to Florida’s border with Alabama, and from the Anclote to Anna Maria Island.
Governors in at least three states have declared emergencies, and the local authorities are urging people to evacuate or to fortify their homes ahead of the storm.
Florida Governor Rick Scott called Michael “monstrous storm” and urged residents to listen to officials.
Despite the warnings, local officials believe a far smaller number of people have in fact moved away.
Schools and state offices in the area are to remain shut this week.
On Tuesday, Gov Scott said he had activated 2,500 Florida National Guard troops.
Governor Scott warned residents about the dangers of the approaching hurricane, with the potential to make landfall as a Category 4 storm.
He pleaded with residents on Tuesday to heed evacuation orders and to prepare for a storm that he warned “could bring total devastation to parts of our state.”
“Hurricane Michael is a monstrous storm, and the forecast keeps getting more dangerous,” Mr. Scott said during an appearance at the state’s emergency operations center in Tallahassee, the Florida capital.
North Carolina Governor Roy Cooper told residents: “I know people are fatigued from Florence, but don’t let this storm catch you with your guard down.”
More than 300 miles of coastline are currently under threat, the National Weather Service has said.
Forecasters in Alabama warned of possible tornados.
President Donald Trump told reporters on Tuesday: “We are very well prepared for the incoming hurricane.”
Heavy rains are forecast for the Carolinas, which were drenched by Hurricane Florence last month.
Hurricane Michael was upgraded to a Category 2 storm as it barreled toward the Gulf Coast. It could hit Florida as a Category 3 hurricane.