High Quality Content by WIKIPEDIA articles! The 2004 Pacific hurricane season had twelve named storms – the fewest in a season since 1999. It officially started on May 15, 2004 in the eastern Pacific, and on June 1, 2004 in the central Pacific. The season officially ended on November 30, 2004, in both portions of the Pacific Ocean. These dates conventionally delimit the period of each year when most tropical cyclones form in the northeastern Pacific Ocean.