Summary of 2004 Atlantic Basin Tropical Cyclone Activity and Verification of Seasonal Forecasts

摘要

The 2004 Atlantic basin tropical cyclone season was one of the most active and destructive on record. A total of fourteen named tropical cyclones (sustained winds >= 39 mph), nine hurricanes (sustained winds >= 74 mph), and six intense or major hurricanes (sustained winds >= 111 mph) developed during the season. These six major hurricanes lasted for 22.25 days, which is the most major hurricane days since the 1926 season. The primary reason that the 2004 season will be remembered is the intense destruction that the season caused along the Southeast United States coastline. Hurricanes Charley, Frances, Ivan, and Jeanne combined to cause an estimated $20 billion to $25 billion in insured damage (～$40 billion to $50 billion in actual loss), making this the most destructive year on record. Some of the features present during the 2004 season that combined to make the season so active and destructive were a strong equatorial trough, warm Atlantic sea surface temperatures, reduced vertical wind shear, and a persistent high pressure off the east coast of the United States. In this paper, the authors also verify their 2004 seasonal forecasts issued at vari- ous lead times.