The center is expected to pass just to the west of the state's capital. That ranked as the most expensive storm in U.S. history, until Hurricane Katrina inundated New Orleans and pummeled other parts of the U.S. South in 2005.
Hurricane Michael is on track to be the strongest hurricane to hit the USA in 50 years, and the third strongest ever.
Based on wind speed, Michael is the fourth-strongest US -landfalling hurricane, behind Andrew, Camille in 1969, and the biggest one of all, an unnamed 1935 Labor Day storm that had winds of 184 miles per hour. "Additional strengthening is expected, and Michael is forecast to be a major hurricane at landfall in Florida", the NHC said in its latest advisory.
Scott, a Republican running for the US Senate in November's congressional elections, declared a state of emergency in 35 Florida counties. Rick Scott posted a series of tweets warning residents to prepare and evacuate.
Hurricane Michael is nearing the Florida Panhandle and Panama City as a "potentially catastrophic" Category 4 storm, with maximum sustained winds of 150 miles per hour, the National Hurricane Center says.
Meanwhile the Bay County Sheriff's Office warned residents that a "shelter-in-place" order has been issued, and urged everyone to stay off the roads.
The projected path of the storm remains unchanged.
As the rain makes it way into the area, so will stronger, tropical storm force winds.
Thunderstorms capable of producing some isolated damaging wind gusts are possible in the afternoon and evening.More news: President Donald Trump Tweetstorm - The Saturday Edition
The Gulf Coast gets bigger storm surges because the water is shallow just off shore, so it can pile up.
The storm's power is shown in the dramatic drop in its minimum central pressure, which was measured at 937 millibars at 7 a.m.by Air Force Reserve Hurricane Hunter aircraft.
Michael also had hot towers - tall thunderstorms that form in the eyewall of a hurricane - and these storms release heat that all the water vapor condenses into cloud water.
Based on its internal barometric pressure, Michael was the third most powerful hurricane to hit the USA mainland, behind the unnamed Labor Day storm of 1935 and Camille in 1969.
As if one cyclone weren't enough, Hurricane Michael could cause tornadoes in several states.
Tyndall is home to the 325th Fighter Wing.
The storm is a category three out of five on the Saffir-Simpson hurricane wind scale. At the time, the then-tropical-storm wasn't expected to achieve its current Category 4 status, but now that it's here, it's time to batten down the hatches.
Myers said Hurricane Michael will likely be less destructive than Hurricane Florence, which caused an estimated $60 billion in overall damage and economic impact, because the storm is moving at a faster pace and will likely cause less inland flooding.
"I think that if people are comparing storms, what was really fascinating was that it was still intensifying when it was making landfall, which is similar to Hurricane Camille also intensifying as it moved inland", says AccuWeather Senior Meteorologist Dan Kottlowski.
At 2:00 a.m. Wednesday, the eye of Michael was about 180 miles (289 kilometers) south-southwest of Panama City, Florida.