Florida's governor mobilized National Guard troops and thousands of Gulf Coast residents were ordered evacuated on Monday, two days before Hurricane Michael was forecast to slam ashore with life-threatening waves, winds and rains.
Hurricane Michael is expected to strengthen rapidly over the next 24 to 36 hours and will be "a risky major hurricane when it reaches the northeastern Gulf Coast on Wednesday", the National Hurricane Center says.
"This is a part of the Gulf of Mexico that is incredibly vulnerable to storm surge", he said. Many trees will be snapped or uprooted, blocking numerous roads.
"Heavy rainfall from Michael could produce life-threatening flash flooding from the Florida Panhandle and Big Bend region into portions of the Carolinas through Thursday", the hurricane center said.
Hurricane Michael was about 485 miles south of Panama City, Fla., at 11 p.m. ET Monday, the National Weather Service said, and was moving north at 12 mph. Hurricane-force winds extended outward up to 40 miles (64 kilometres) from the core and tropical-storm-force winds out 195 miles (313.81 kilometres).
In an advisory Monday morning, the National Hurricane Center suggested the storm would make landfall Wednesday as a Category 3 hurricane, with sustained winds of at least 111 miles per hour. But within hours, it gained more punch and its top sustained winds clocked in at 60 mph by late Sunday evening.
The hurricane's sustained winds are expected to hit up to 120 miles per hour by late Tuesday, making it a major hurricane - the designation for Category 3 storms and above, on the Saffir-Simpson wind scale.
The hurricane caused major flooding in the Florida Panhandle and significant damage, according to local news media reports.
Among the actions taken by state agencies to prepare for the storm's impacts and subsequent recovery efforts, the Florida National Guard as of October 9 had activated 2,500 soldiers and airmen for pre-landfall coordination and planning, with an emphasis on high water and search and rescue operations.
A tropical weather system has rapidly strengthened into Hurricane Michael and is likely to keep growing stronger ahead of an expected strike on Florida's Panhandle by midweek, forecasters said.
Storm and storm surge watches were issued for the Gulf Coast from the Mississippi-Alabama border to Chassahowitzka, Florida, north of Tampa Bay.
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 center data. Hurricane Michael in the Caribbean could have also contributed. On average, the Atlantic would have about five hurricanes by October 8.
Michael was lashing western Cuba late Monday morning with heavy rains and strong winds, according to the hurricane center.
"You've got to take care of yourself", said Scott, sporting his faded Navy baseball cap that has become a hallmark of his past emergency attire, after a briefing at the Bay County Emergency Operations Center in Southport.
"EVERY FAMILY must be prepared".
"Everybody's got to get ready". "Don't take a chance". "We know that a storm like Michael can be devastating and deadly".
The governor declared a state of emergency for Escambia, Santa Rosa, Okaloosa, Walton, Holmes, Washington, Bay, Jackson, Calhoun, Gulf, Gadsden, Liberty, Franklin, Leon, Wakulla, Jefferson, Madison, Taylor, Hamilton, Suwannee, Lafayette, Dixie, Columbia, Gilchrist, Levy and Citrus counties.
Lines at gasoline stations were growing long in Panama City as people prepared to leave areas under mandatory evacuation, Trepanier said.
Neighbours in Alabama - the entire state is under an emergency declaration - also were bracing.
A tropical storm warning is in effect for the Cuban province of the Isle of Youth and the coast of Mexico from Tulum to Cabo Catoche, including Cozumel.
A hurricane warning is in effect for the Cuban province of Pinar del Rio. "Tropical storm conditions are expected across the remainder of the warning areas in Cuba and the Yucatan Peninsula through tonight", the center said.
Alabama Gov. Kay Ivey declared a state of emergency in her state, "in anticipation of widespread power outages, wind damage and debris produced by high winds and heavy rain associated with Hurricane Michael".