Officially, the Atlantic hurricane season ended on November 30, though tropical storm Olga held on into early December. With 15 tropical storms, nine of which became hurricanes, this was the fourth straight year with above-average tropical activity. The averages are ten tropical storms and six hurricanes.

Despite this year's big numbers, few storms threatened the United States. In fact, for the second straight year, no hurricane made landfall in the U.S. That's not only unusual, but it's a record, partly due to luck and partly to persistent upper-level westerly winds near the East Coast that have tended to steer storms away. Hurricane Michelle did graze Florida in early November, while three tropical storms actually made landfall - Barry and Gabrielle in Florida and Allison in Texas.

Allison was by far wreaked the most havoc. Its torrential rains back in June caused at least 40 deaths and more than $5 billion in damage from Texas to Pennsylvania, reminding us that a tropical system doesn't have to be a hurricane to cause a catastrophe.