When Hurricane Michael crashed into the coast of the Florida Panhandle as a strengthening Category 4 storm, it packed maximum sustained winds of 155 mph and a central pressure of 919 millibars. Based on these two key measures of intensity, it ranked among the top four most-powerful hurricanes to hit the United States.
The Florida Panhandle, which was devastated by Michael, has no prior record of such a strong storm. Incredibly, Michael was still a major (Category 3) hurricane when it tracked into Georgia early Wednesday evening, becoming the most intense storm to hit the state since 1898.
Michael made history by intensifying at a mind-boggling pace. It was a tropical depression on Sunday morning. At the time of landfall near Mexico Beach on the Panhandle early Wednesday afternoon, the storm was 1 mph shy of Category 5 status.
The extent of Michael’s devastation in Florida and other parts of the Southeast is still being assessed, but it is certain that there will never be another Hurricane Michael in the Atlantic, the Caribbean or the Gulf of Mexico, as its name will be retired at the end of the 2018 Atlantic hurricane season.
Michael’s maximum sustained winds of 155 mph at the time of landfall place it at fourth-strongest, behind only the three Category 5 hurricane landfalls in the continental United States: Labor Day (1935), Camille (1969) and Andrew (1992).
It ranked as the third-strongest storm to hit Florida, based on wind, and second-strongest, based on pressure.
And now that #HurricaneMichael has made landfall, here is where it sits in Florida's hurricane history... pic.twitter.com/g8az7OOeN1
— Brian McNoldy (@BMcNoldy) October 10, 2018
When using minimum sea level pressure as a metric for intensity, Michael’s landfall pressure of 919 millibars was the third-lowest on record in the United States, trailing only the Labor Day Hurricane of 1935 (892 millibars) and Camille in 1969 (900 millibars). Its pressure was the lowest on record for any October hurricane to strike the United States.
Pressure is often used as a metric to evaluate storm intensity, because a hurricane’s winds are directly related to how much the pressure changes over a relatively small distance. Larger storms need to have lower pressure to have the same wind speed as smaller storms. Consequently, storms with lower pressures tend to do more damage.
Based on its astonishingly low pressure, Michael was much stronger than any hurricane on record to make landfall in the Florida Panhandle, as shown in the tweet below.
#HurricaneMichael 1030a CDT position and pressure per @NHC_Atlantic, compared to IBTrACS historical data points. Red are sub 900 pressures, orange 900-923 mb. Storm still deepening per recon. #rarebird pic.twitter.com/JSZR9kC5Sf
— Ian Livingston (@islivingston) October 10, 2018
The strongest hurricanes to hit the Florida Panhandle before Michael (based on maximum sustained wind) were the Pensacola Hurricane of 1882 and Eloise in 1975, both of which were Category 3 with 125 mph winds at landfall. Michael broke that record by a whopping 30 mph and became the first Category 4 hurricane on record to hit the Panhandle.
Michael’s place in Georgia hurricane history has also been etched.
After making landfall in Florida, it was still classified as a major (Category 3) hurricane when it tracked into southwest Georgia. No major hurricane has tracked into Georgia since 1898, when the Georgia Hurricane made landfall in Camden County as a Category 4.
In a season that was expected to be somewhat tame and is now running slightly above normal, a storm like Michael is a good reminder that it doesn’t take an extremely busy hurricane season for big problems to arise.