Earlier it said Michael could produce three life-threatening hazards along portions of the northeastern Gulf Coast: storm surge, heavy rainfall, and hurricane-force winds, with storm surge and hurricane watches in effect.
Hurricane Michael is packing winds of 145mph as it churns through the ocean and is expected to make landfall this afternoon local time (this evening BST).
"This storm will be life-threatening and extremely risky", Scott said Sunday after receiving a briefing at the State Emergency Operations Center.
"Impacts from Hurricane Michael along the Florida Panhandle will include a risky storm surge, flooding rainfall and damaging winds".
The sinister-looking skull appeared briefly on the National Oceanic and Atmospheric Administration satellite images on Tuesday as the hurricane moved closer to the Florida Panhandle.
Tallahassee´s Democratic Mayor Andrew Gillum, who is campaigning to succeed Scott as governor in next month´s elections, suspended his campaign and returned to the state capital to oversee storm preparations.
People visit the beach while waiting for Hurricane Michael in Panama City Beach, Florida.
Northwest Florida as a region attracted almost 17 million visitors in 2016, or 15 percent of total tourists in the state, according to Visit Florida, the state's tourism marketing arm.
While the storm loomed over the Gulf of Mexico on Tuesday, cameras aboard the International Space Station captured views of Hurricane Michael at 12:13pm and 12:50pm ET.
The Commodity Weather Group said Michael was not likely to cause much interruption to oil and gas production.
Anxious meteorologists said it had the potential of becoming one of the worst storms in the history of Florida's Panhandle.
"If this trend continues overnight, people in the Florida Panhandle could wake up to having a Category 4 hurricane on their doorstep", senior NHC hurricane specialist Stacy Stewart said during a live webcast.
He warned that storm surge could affect areas of Florida not in the storm's direct path.
Forecasters in Alabama warned of possible tornados. Scott expanded the order on Monday to encompass 35 counties.
Scott said that he's called up 2,500 members of the National Guard to assist, and has more than 1,000 rescuers at the ready.
The storm caused widespread destruction in Central America over the weekend, where at least 13 people have been reported dead.