Accumulated cyclone energy: The Pacific has it
The hyperactive Pacific is reflected in year-to-date statistics on accumulated cyclone energy (ACE) compiled by Phil Klotzbach using data from the National Hurricane Center and Joint Typhoon Warning Center. ACE takes into account the strength as well as the longevity of tropical cyclones, but not their size. Through October 19, the Northeast Pacific ACE (184% of year-to-date average) was on track to end up in second place behind 1992; the Northwest Pacific ACE (189% of year-to-date average) was at record levels for the time of year; and the Central Pacific ACE was at an astounding 606% of its year-to-date average, partly a reflection of the many years that feature little activity in that basin. Within the next day or so, according to Klotzbach, Hurricane Olaf should push the Central Pacific past 1994 to set the basins all-time seasonal record. The North Atlantic is at a mere 62% of its year-to-date average, but the prolific Pacific has still pushed the entire Northern Hemisphere to a new year-to-date ACE record as of October 20, says Klotzbach.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=3160