the accumulated cyclone energy (ACE) index for the 2004 Atlantic hurricane season as calculated by Colorado State University using data from the National Hurricane Center was 226.9 units, one of the highest values on record in the basin. ACE is, broadly speaking, a measure of the power of the hurricane multiplied by the length of time it existed, so storms that last a long time, as well as particularly strong hurricanes, have high ACEs. It is only calculated for full advisories on tropical systems at or exceeding , which is tropical storm strength. The 2004 season was very deadly, with about 3,270 fatalities overall. Nearly all of the deaths were reported in Haiti following the floods and mudslides caused by Tropical Storm Jeanne. The other tropical cyclones that caused fatalities include Hurricane Alex, Charley, Frances, Gaston, and Ivan, and Tropical Storms Bonnie and Earl. Because four out of the six major hurricanes made several landfalls, the season was also extremely damaging, with losses estimated at $60.9 billion, over half of which was caused by Hurricanes Charley and Ivan. A few other tropical cyclones caused light to moderate damage, including Hurricanes Alex and Gaston and Tropical Storms Bonnie and Matthew. In addition to the 16 tropical cyclones of the season, a tropical low in May brought torrential flooding to Haiti and the Dominican Republic, killing 2,000 people and causing extensive damage. Although the system was not officially classified as a tropical storm, it did have a circulation with loosely organized convection, resembling a subtropical cyclone. Records The 2004 season had numerous unusual occurrences and set many records. However, most of them were surpassed by the following year. With six hurricanes reaching at least Category 3 intensity, 2004 also had the most major hurricanes since 1996, a record which would be surpassed in 2005. Florida was directly impacted by four major hurricanes during the season – Hurricane Charley, Frances, Ivan, and Jeanne. This was the first time four tropical cyclones produced hurricane-force winds in one state during a single season since four hurricanes made landfall in Texas in 1886. There were many other hurricanes in the season that were individually unusual. Hurricane Alex was the strongest hurricane on record to intensify north of 38°N latitude. Hurricane Ivan was the most unusual storm of the season. Ivan became the southernmost Category 4 hurricane on record in the Atlantic basin, as well as the