Florida's governor mobilized National Guard troops and ordered Gulf Coast residents to evacuate as Hurricane Michael churned toward shore on Monday, with "life threatening" storm surges, winds and flooding feared when it makes landfall on Wednesday.
Michael was expected to become a major Category 3 storm by Tuesday with winds over 100 miles per hour (160 km per hour), making it the most powerful storm to hit the Panhandle of Florida in over 15 years.
The storm was forecast to bring up to 12 inches (30 cm) of rain with storm surges up to 12 feet (3.7 meters) in the Florida Panhandle, according to the US National Hurricane Center (NHC). Michael was currently a Category 1 hurricane, at the bottom of the five-step Saffir-Simpson scale.
Florida Governor Rick Scott declared a state of emergency in 35 counties along the Florida Panhandle and Big Bend. Mandatory evacuations were underway in coastal areas, with 1,250 National Guard soldiers aiding the process and over 4,000 troops on standby, Scott tweeted.
"The FL panhandle needs to be prepared for a direct hit with sustained hurricane force winds," Scott wrote on Twitter on Monday.
In neighbouring Alabama, Governor Kay Ivey declared an emergency for the entire state on Monday in anticipation of wind damage, heavy rains and power outages.
MICHAEL KILLS 13 IN CENTRAL AMERICA
As the storm moved north it battered Mexico's Yucatan Peninsula and western Cuba with drenching rains and winds of up to 80 mph (130 kph), the Miami-based hurricane centre said.
Heavy rains and flash-flooding over the weekend caused 13 deaths in Central America after Michael formed off the coast of northern Honduras.
In Florida, state offices, schools and universities were set to close Tuesday through the end of the week in panhandle counties. Beach town residents were deciding whether to leave their homes.
"I haven't made up my mind yet, but I know some of my staff are going," said Dave Trepanier, owner of Firefly, a restaurant a block from the beach in Panama City, Bay County, an area where the hurricane is expected to come ashore.
Lines at gas stations were getting long in Panama City as people prepared to leave areas under mandatory evacuation, Trepanier said.
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 hitting Florida, the storm is forecast to move up the East Coast on Wednesday and Thursday and batter the Carolinas, which are still recovering from Hurricane Florence last month.
Energy companies halted nearly a fifth of Gulf of Mexico oil production and evacuated staff from 10 platforms on Monday as Michael was forecast to become the strongest of three named storms to affect the US Gulf of Mexico this year.
Exxon Mobil Corp, BP Plc, BHP Billiton Ltd and Equinor ASA each pulled staff from production platforms and others were monitoring conditions.
The Gulf of Mexico is home to 17 per cent of daily US crude oil output and 5 per cent of daily natural gas output, according to the US Energy Information Administration.