Hurricane Michael has strengthened to a Category 2 storm as it heads for the Florida Panhandle, with residents ordered to get out of harm's way ahead of life-threatening waves, winds and rains.
Tens of thousands of people were told to evacuate the coastal areas in nine counties as the storm moved over the Gulf of Mexico, carrying winds of 155km/h and disrupting oil production.
Michael could grow to a Category 3 storm on the five-step Saffir-Simpson scale before it makes landfall on Wednesday (local time), forecasters said, potentially the most powerful storm to strike the Panhandle in at least a decade.
"Hurricane Michael is a monster storm and it keeps getting more dangerous. We're 12 hours away from seeing impacts," Florida Governor Rick Scott told a news conference on Tuesday.
"The time to prepare is now."
He warned of potential deadly impacts from a storm surge that could be as much as 3.7 metres over normal sea water levels, and winds that could rise to 77 km/h.
People in potentially affected areas should not take any chances against such a large storm surge, Mr Scott said. "No one's going to survive," such a wall of water, he added.
As Michael moved over open water, energy companies halted nearly one-fifth of Gulf of Mexico oil production and evacuated personnel from platforms.
The storm was forecast to make landfall somewhere over the Florida Panhandle or Florida Big Bend area on Wednesday, the National Hurricane Center forecast.
The centre warned residents along more than 480 km of coastline, from the Alabama/Florida border to the Suwannee River in Florida, to brace for hurricane conditions.
As much as 30 cm of rain was also forecast across Florida, Georgia and South Carolina, the NHC said.
Scott declared a state of emergency in 35 counties along the Panhandle and Florida's Big Bend regions. About 1,250 National Guard soldiers were assisting and more than 4,000 troops were placed on standby.
State offices, schools and universities were closed through the end of the week in Panhandle counties. Lines at gasoline stations grew as people left. Those who stayed emptied grocery store shelves of water and other supplies.
In neighbouring Alabama, Governor Kay Ivey declared an emergency for the entire state on Monday, anticipating wind damage, heavy rains and power outages.
Hurricane Michael would be the first major hurricane to hit the Panhandle since Hurricane Dennis in 2005, which made landfall near Pensacola, according to hurricane centre data.
After striking Florida, Michael is forecast to move up the East Coast on Wednesday and Thursday through the Carolinas, which are still recovering from Hurricane Florence.
Reuters
