If it seems like this year's hurricane season came and went with only a whimper, it was probably even more benign than you think. Rated by the total amount of storm energy for the entire season, the 2007 hurricane season was much weaker than the 1950-2000 average.

The Accumulated Cyclone Energy (ACE) for the season is a calculation of total storm energy based on maximum wind speeds and how long each storm lasts. Based on calculations by the Tropical Meteorology Project at Colorado State University, the ACE for this year was 68. The average ACE for the years 1950-2000 is 96. The ACE forecast on May 31 was 170.

The number of tropical storms was slightly above average and the number of hurricanes was average. What made the season so weak was that most of the storms did not last very long. Additionally, there were only four landfalls on the U.S. coasts.

All forecasts for the 2007 hurricane grossly over-estimated the intensity of the season. Researchers are struggling to understand why this season was so weak. One theory, according to the Tropical Meteorology Project, is that wind shear over major sections of the Atlantic effectively destroyed developing storms and in some cases, especially during October and November, limited cloud organization so that storms could not form.   

The season featured two Category 5 hurricanes. Hurricane Dean hit the east coast of the Yucatan Peninsula with 165mph winds on August 21. The National Hurricane Center attributes approximately 40 deaths across the Caribbean to Dean.

Hurricane Felix was the season's most destructive storm. Felix made landfall as a Category 5 storms near Punta Gorda, Nicaragua on September 4. Over 100 persons were killed, and major damage occurred over large areas of Central American and the Caribbean.

The United States was spared significant damage from hurricanes this year. Tropical Storm Barry made landfall near Tampa in early June then moved northeast across southern Georgia and the coastal Carolinas. Barry brought much needed rain to southeast Georgia and effectively ended the Okefenokee Swamp fires.

Tropical Storm Erin made landfall near Corpus Christi, Texas in mid August. Erin quickly weakened but produced flooding rains over large portions of Oklahoma, Texas, Missouri, and Arkansas.

Tropical Storm Gabrielle grazed the North Carolina coast making a brief landfall near Cape Lookout on September 9. Very little damage was reported.

Hurricane Humberto off the Texas coast on September 12. Image Courtesy NASA.

Hurricane Humberto hit the northeast Texas coast midway between Galveston and Port Arthur on September 13. Flooding rains occurred over portions of east Texas, Louisiana, and Mississippi.

Details of the 2007 Hurricane season can be found at the National Hurricane Center.