What happened to the hurricanes?

The end of November marks not only the start of nonstop Christmas music on the radio, but also the end of the Atlantic hurricane season. And for the second year in a row, forecasters overestimated the severity of the season.

In their annual summary, Phil Klotzbach and William Gray of Colorado State University reported 14 named storms, six of them hurricanes and two of those intense (winds over 111 mph); their May prediction called for 17, nine and five, respectively. In their defense, government forecasters also got it wrong: They predicted seven to nine hurricanes, three to five of them intense.

Klotzbach explained the 2007 season to me best: “a bunch of wimpy crap and two Category 5s.” Indeed, it was a strange season: only one hurricane made landfall in the U.S., and the only two strong storms happened to be monsters (Dean and Felix) responsible for more than 150 deaths in the Caribbean.

Since the infamous 2005 season (seven intense hurricanes, including Katrina), the Atlantic has been strangely average at a time when forecasters have been predicting far stormier times. This relatively tame season also comes after the Intergovernmental Panel on Climate Change issued its February report linking stronger hurricanes to human-induced global warming.

It will be interesting to see if the 2008 season goes back to the active trend we’ve seen since the 1990s or if it falls below expectations for the third consecutive year. Klotzbach and Gray just released their first 2008 forecast, calling for an above-average season.

For more on hurricanes, check out Jeremy Hsu’s story on New York and the next big one.