A Relentless Hurricane Season

Tropical Storm Wilma has officially developed into the 12th hurricane of the 2005 season, and experts predict it will reach Florida by the weekend.

At press time, Wilma is packing 75-mph winds, moving from the northwestern Caribbean Sea toward the Gulf of Mexico.

According to the National Oceanic and Atmospheric Administration (NOAA), we’re in Guinness Book of Records territory: This year, there have been 21 named storms, 11 of which have become hurricanes—five of which were major. During an average hurricane season, which runs from June 1 to Nov. 30, there are 10 named storms and six hurricanes, two of which are major.

“With one additional hurricane, this season will tie 1969 for having the most hurricanes,” says Scott Kiser, tropical cyclone program manager for the National Weather Service.

By now, all of us are used to hearing about hurricane categories, which are based on a five-point scale. In fact, most Americans are speaking weather-ese and abbreviating them (“a cat 3 is about to hit”). But what do these numbers actually mean?

The following NOAA chart describes hurricane intensity and potential property damage.