Hawai'i's 2006 hurricane season spared the Islands but saw five tropical weather systems in central Pacific waters — including the most powerful storm ever to originate in the region.

Hurricane Ioke spun into being Aug. 20, and while it never threatened Hawai'i, the system developed into a monster that caused damage both on islands west of Hawai'i and in Alaska. It holds the record for having remained at Category 4 or stronger longer than any other tropical cyclone ever observed. Category 4 hurricanes have winds stronger than 130 miles an hour.

The hurricane season started slowly this year, but a fast-developing El Niño condition warmed the waters south of Hawai'i and contributed to the development of Ioke as well as the three tropical depressions that formed in late September and early October, said Andy Nash, director of operations for the National Weather Service's Central Pacific Hurricane Center.

"It ended up being a near-normal season" thanks to the development of the El Niño-related storms late in the year, he said. "El Niño started getting going during the summer."

The year was unusual in part because most tropical storms in the Central Pacific are formed in the Eastern Pacific and move westward into the waters near Hawai'i, Nash said. This year only the first storm of the season, late July's Hurricane Daniel, followed that pattern. Daniel was already weakening as it passed 140 degrees west longitude — the line between the eastern and central Pacific regions — and passed south of the Islands as a remnant low-pressure system.

Nash said this El Niño remains a fairly weak one, but it could create conditions that promote a dry winter. El Niño is the name for a climate event that is often associated with warmer than usual water near the equator.

"During El Niño, we can get a drier than normal winter, especially from this time of the year onward," Nash said. He said a persistent high-pressure zone in the area helps prevent kona low pressure systems and cold fronts from bringing normal winter rains.

Nash said the El Nino is expected to persist at least into early 2007, but it is too early to predict whether it will have an impact during the 2007 hurricane season, which starts at midyear.

MAJOR STORMS BLOW PAST STATE

There were two hurricanes and three tropical depressions in the Central Pacific this year.