High Quality Content by WIKIPEDIA articles! The 2004 Pacific hurricane season had 17 tropical cyclones, of which 12 became named storms, 6 became hurricanes, and 3 became major hurricanes (Category 3 or higher). This timeline documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation. It also includes information which was not operationally released, meaning that information from post-storm reviews by the National Hurricane Center, such as information on a storm that was not operationally warned on, have been included. The season officially began on May 15, 2004 in the eastern Pacific proper (June 1, 2004 in the central Pacific) and lasted until November 30 that same year. Areas east of 140°W are under the purview of the National Hurricane Center (NHC); the area between the International Date Line and 140°W, or the central Pacific, is under the purview of the Central Pacific Hurricane Center (CPHC).