Wind gusts of 35 miles per hour or more are likely along the coast and could bring down trees and powerlines and rip tarps off homes damaged by Florence, Cooper said.
Projections say there is little chance of Hurricane Michael making a hard turn to the right, and into the peninsula.
In a 5 p.m. update on October 9, the National Hurricane Center (NHC) said Michael has strengthened to a "major hurricane" and has life-threatening storm surge, hurricane-force winds, and heavy rainfall.
Previous year saw a string of catastrophic storms batter the western Atlantic - including Irma, Maria and Harvey, which caused a record-equaling $125 billion in damage when it flooded the Houston metropolitan area. Landfall is expected Wednesday on Florida's northeast Gulf Coast. "On the forecast track, the center of Michael will move across the eastern Gulf of Mexico through tonight", the agency said. Damaging winds will also extend inland across portions of the Florida Panhandle, southern Georgia and southeast Alabama as Michael moves inland.
Three Florida Panhandle counties have issued mandatory evacuation orders ahead of Hurricane Michael's expected landfall. Weakening is expected after landfall as Michael moves across the southeastern United States.
As the storm moved north it battered Mexico's Yucatan Peninsula and western Cuba with drenching rains and winds of up to 80 miles per hour (130 kph), the Miami-based hurricane centre said.
Michael battered parts of Mexico and Cuba with powerful winds and drenching rain on Sunday and into early Monday (local time).
AccuWeather chief Joel Myers said Michael is forecast to roll through the region much more quickly than did the lingering Florence, which dumped up to 40 inches of rain in some areas. Hurricane Michael in the Caribbean could have also contributed.
On the Panhandle, Escambia County Sheriff David Morgan warned residents during a news conference Monday evening that if they stay, first responders won't be able to reach them during the storm or immediately after.
"This storm can kill you".
"If you're responsible for a patient, you're responsible for the patient".
With an officiant standing in front of them, the couple said their vows on the beach as brisk winds brushed them. The county has opened two sandbag locations for residents.
Areas likely to be hardest hit include the Crestview-Fort Walton Beach area, Panama City and Florida's state capital, Tallahassee.
"Guess what? That's today", National Hurricane Center Director Ken Graham said.
"This is a part of the Gulf of Mexico that is incredibly vulnerable to storm surge", Graham said.
In the small Panhandle city of Apalachicola, Mayor Van Johnson Sr. said the 2,300 residents are frantically preparing for a major hurricane strike that could be unlike any there in decades.
Cars there were in long lines at one of the town's gas stations Tuesday.
Since the Sunshine State has been battered by so many hurricanes, including the destructive Hurricane Andrew in 1992, Floridians are better prepared to handle flooding than virtually any other state.
Some areas along the state's Big Bend area could see unsafe storm surge between six and 12 feet as Michael nears, the Hurricane Center reported.
Franklin County emergency officials issued a mandatory evacuation for all non-residents and Wakulla County emergency officials plan to announce a mandatory evacuation for coastal and low lying locations by 8 p.m. Monday night.
With just a month to go before Election Day, Florida voters in evacuation zones were given an extra day to register to vote, once offices reopen after the storm.