How Michael grew into a monster

WASHINGTON — Moist air, warm waters in the Gulf of Mexico and ideal wind patterns supercharged Hurricane Michael before it smacked Florida’s Panhandle.

Michael was barely a hurricane Tuesday morning, with winds of 90 mph. A little over a day later, it had transformed into a monster. When it made landfall Wednesday afternoon, it was blowing at 155 mph, a 72 percent increase in wind speed in less than 33 hours.

“Michael saw our worst fears realized, of rapid intensification just before landfall on a part of a coastline that has never experienced a Category 4 hurricane,” University of Miami hurricane researcher Brian McNoldy said Wednesday morning.

Hurricanes have something called a potential intensity. Michael had nothing holding it back.

“Everything was there for it to reach its potential, and it did,” National Oceanic and Atmospheric Administration climate and hurricane expert Jim Kossin said.

Another factor: Its pressure, which meteorologists use to gauge a hurricane’s strength. The lower the pressure, the stronger the storm. Before landfall, Michael’s pressure fell so low it looked like the winds were sure to pick up fast, said Ryan Maue at weathermodels.com.

Another huge factor was the water temperature. Warm water fuels hurricanes and the Gulf water is 4-5 degrees warmer than normal.

The warm waters, Kossin said, are a “human fingerprint” of climate change.

A study this year in Geophysical Research Letters found that since 1986, the rate of intensification of storms like Michael has increased by about 13 mph.