The new landfall speed was determined by a review of the available aircraft winds, surface winds, surface pressures, satellite intensity estimates and Doppler radar velocities, NOAA said. That includes data and analyses that weren’t available during the storm. The increase in the estimated maximum sustained wind speed from the operational estimate is small and well within the normal range of uncertainty, NOAA said.
In addition to Hurricanes Michael and Andrew, the only other Category 5 storms known to have made landfall in the U.S. are the Labor Day Hurricane that hit the Florida Keys in 1935 and Hurricane Camille, which ravaged the Mississippi coast in 1969. Michael is also the strongest hurricane landfall on record in the Florida Panhandle and only the second known Category 5 landfall on the northern Gulf coast.
Besides wind speed, atmospheric pressure is also used to measure storm intensity, with a lower central pressure generally meaning higher winds. Michael’s central pressure at landfall is the third lowest on record for a landfalling U.S. hurricane since reliable records began in 1900, trailing only the Labor Day Hurricane of 1935 and Hurricane Camille of 1969.