Corelogic noted the compact nature of hurricane Michael, which will have limited the size of the swathe of damage on landfall, but the storm surge has impacted a wide area from Mobile, AL to Tampa, FL, with the maximum storm surge anticipated to be east of Panama City to coastal cities south of Tallahassee, the firm said.
Meanwhile, Michael continues its track across southern Georgia toward the Carolinas.
Olivia Smith, public information officer for the Gadsden County Board of County Commissioners, said there was "one hurricane-related fatality", adding that the incident was "debris-related".
The hurricane is expected to make landfall Wednesday, with population centers like Panama City and Tallahassee sitting in its path.
Videos are emerging of the destruction the hurricane is causing across the region.
As of the 5 p.m. advisory, Michael is an extremely unsafe Category 3 storm. They said Michael could be the strongest hurricane to hit that stretch of coastline in 13 years. As the tropical storm continued to weaken it was still menacing the US Southeast with heavy rains, blustery winds and possible spinoff tornadoes.
Damage in Panama City near where Michael came ashore Wednesday afternoon was so extensive that broken and uprooted trees and downed power lines lay almost everywhere.
Measured in this way the lower the pressure the stronger the hurricane - Michael was the most powerful since Hurricane Camille in 1969.
Michael was a monster storm by wind speed around the time it made landfall.
Long, the head of FEMA, said many Florida buildings were not built to withstand a storm above the strength of a Category 3 hurricane on the five-level Saffir-Simpson Hurricane Wind Scale.
While there may be no civil implications for staying, Gov. Rick Scott reiterated the dangers of remaining in a hurricane evacuation zone.
Two to three inches of rain is expected for the area during the storm as well.
"It feels like a nightmare", she said."Looking at the pictures, I'm thinking there is not a house left in that town".
As of around 8pm, Michael was about 20 miles southwest of Albany, Georgia, with winds of 100 mph, becoming a category 1 storm. "The emergency declaration is effective for seven days and makes all state resources available to local governments and entities within the impacted area of the hurricane", his office said. "Do not risk your life, leave NOW if you were told to do so", it said.
At Tyndall Air Force Base south of Panama City leaders declared HURCON (Hurricane Condition) 1 status, ordering out all but essential personnel, after some 600 military families appeared squarely targeted for the worst of the storm's fury.
The governors of North and SC urged residents to brace for more heavy rain and storm-force winds as Michael ploughs northward up the Atlantic seaboard.
Scientists say global warming is responsible for more intense and more frequent extreme weather, such as storms, droughts, floods and fires.