Aloha, hurricane season — Eastern Pacific was most active in 22 years

It’s been a hurricane season for the history books.

The Aloha State says goodbye today to a 2014 hurricane season that set precedents on several fronts, including three cyclones cranking in its neighborhood at once and a direct hit on the Big Island by Tropical Storm Iselle.

Hawaii Island also had a brush with the Central Pacific basin’s longest-lived system. In all, there were five tropical cyclones in the basin.

“It’s the first time the Big Island had a landfalling system in modern history, dispelling a lot of myths,” said Ray Tanabe, meteorologist in charge at the National Weather Service in Honolulu.

“There were a lot of people who believed a hurricane couldn’t hit the Big Island, that the island somehow protects them,” Tanabe said. “That belief went away.”

The Eastern Pacific had 20 named storms — the highest number since 1992 — in the season which runs from June 1 to Nov. 30.

The Atlantic was at the opposite end of the spectrum, with only eight named storms and one hurricane making landfall. While an El Nino has not yet officially formed, forecasters have pointed to the lull in the Atlantic and the increased activity in the Pacific as indicators that El Nino has already been at work.

“Conditions that favored an above-normal Eastern Pacific hurricane season included weak vertical wind shear, exceptionally moist and unstable air and a strong ridge of high pressure that helped keep storms in a conducive environment for extended periods,” said Gerry Bell, lead hurricane forecaster at the NOAA Climate Prediction Center, in a season overview.

Above normal sea surface temperatures also helped the systems develop.

“The increased activity in the Eastern Pacific and the storms forming closer to Hawaii are all signs of El Nino,” Tanabe said.

Hurricane Amanda offered hints of the season to come when it reared its head off the coast of Mexico on May 22, weeks ahead of the period when such systems are normally born. The cyclone came nowhere near Hawaii, but it spun up record wind speeds for a May hurricane in the Eastern Pacific. Amanda intensified rapidly into a Category 4 hurricane packing 155 mph winds. The cyclone raged for a week, far from shore, then dissipated.

Iselle made landfall Aug. 8 as a high-end tropical storm that battered through Puna, damaging at least 150 homes and leaving 25,000 customers without power. Storm surge swamped shoreline Kapoho residences, knocking some houses off their foundations and sweeping pollution into tide pools. The storm devastated papaya farms and damaged coffee plantations and other agriculture on the southern portion of the island.

Iselle was the second in a chain of three hurricanes that approached from the east. Ahead of Iselle, Hurricane Genevieve moved through the Central Pacific south of Hawaii and eventually intensified into a super typhoon far to the west. Hurricane Julio followed two days behind Iselle but ended up tracking north of the islands.

It was the first time in recorded history that Hawaii had ever been threatened by two hurricanes at once.

Iselle was the first tropical cyclone to hit the Big Island since the Kohala Cyclone of 1871, a storm that was very likely a hurricane but whose features were not well documented.

Hurricane Ana set sights on the Big Island in mid-October. With a 13-day life span, Ana was the longest-lived hurricane on record to form in the Central Pacific, and the season’s final display of force. The system started as Tropical Depression Two-C to the southeast of the archipelago and crawled slowly northwest. At one point, Puna was directly in the forecast track, drawing a collective groan from a districtstill digging out of Tropical Storm Iselle and dealing with a lava flow that threatened Pahoa.

However, a ridge of high pressure kept the cyclone from turning north as much as predicted. Ana passed 150 miles south, sparing the island of its winds but bringing a foot of rain to Mauna Loa’s southeast flank.

As winter progresses and temperatures cool, it becomes less likely a hurricane will form in the Central Pacific. That said, tropical cyclones are possible any time of year, especially during years when El Nino increases water temperatures in the central and east-central equatorial Pacific. Hurricane Ekeka blew up into a Category 3 cyclone far south of Hawaii in February 1992 — a strong El Nino year that kicked off the most active hurricane season on record and one in which Hurricane Iniki devastated Kauai.

Ana initially mimicked Iniki’s approach from warmer waters to the south, which worried Barney Sheffield, the Big Island’s disaster coordinator for the American Red Cross. Ana organized and strengthened, then fell apart repeatedly as it neared.

“The water temperature was really warm. At any time, that thing could have exploded,” Sheffield said.

More than 1,200 people used Big Island emergency shelters during Iselle. When Ana passed, shelters were open and ready, but unused.

Sheffield said it was initially hard to round up enough volunteers to man the island’s 11 shelters. While volunteer effort is still lacking in leeward areas, two storms and a lava flow have sparked new interest in volunteering on the windward side, he said.

“I think next year we’ll be even better prepared,” he said. “I hope we don’t have another season like this next year. But who knows? The new norm is unpredictability.”

Forecasters give 55 to 60 percent odds of a weak El Nino developing this winter, and sea surface temperatures have remained elevated. Recent record-high temperatures recorded on Oahu and Kauai were because of record sea surface temperatures in the waters right around the Hawaiian Islands, Tanabe said.

Email Bret Yager at byager@westhawaii today.com.