WASHINGTON (AP) — Moist air, warm waters in the Gulf of Mexico, and ideal wind patterns aligned to turbocharge Hurricane Michael in the hours before it smacked Florida’s Panhandle.

Hurricane 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. That’s 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. That’s how strong a storm can get if all other factors are aligned, said National Oceanic and Atmospheric Administration climate and hurricane expert Jim Kossin said. Michael had nothing holding it back.

“Everything was there for it to reach its potential and it did,” Kossin said.

As Michael’s eye started coming ashore, it boasted the third lowest central pressure of any storm to hit the United States, behind only a 1935 Labor Day storm and 1969’s Camille.

Meteorologists first got a sense something big could be happening by watching how Michael’s eye changed shape. Early Tuesday, it was oddly shaped and ragged. Later in the morning it started to get better organized, and by Tuesday night real-time satellite imagery was showing the eye getting stronger and scarier by the minute.

Another factor: Its pressure, the measurement 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, a meteorologist for weathermodels.com.

And none of the factors that hold a storm back were present, especially something called “wind shear.” Wind shear is when there’s a mismatch either in speed or direction between winds near the surface and those five to six miles (8 to 10 kilometers) up.

That mismatch “pushes the storm over” or decapitates it, Kossin said. When the wind shear near Michael eased, the storm took off, he said.

“It’s kind of like someone was holding on to it when it was trying to run and they let it go,” Kossin said.

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

By SETH BORENSTEIN, AP Science Writer

Comments

Leave a Reply

Please log in using one of these methods to post your comment:

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.