The number of tropical cyclones predicted for Hawaii this year is down, but preparations for them are up under new building standards adopted by the state last month.
At a news conference Wednesday, Central Pacific Hurricane Center Director Ray Tanabe said forecasters expect two to four tropical cyclones during the hurricane season, from June 1 through Nov. 30, including tropical depressions, tropical storms and hurricanes.
In an average season, there are four to five cyclones.
The Central Pacific Hurricane Center, based in Honolulu, says this year’s outlook calls for a 50 percent chance of a below-normal season, a 30 percent chance of a near-normal season and a 20 percent chance of an above-normal season.
Tanabe said all factors point to a below-normal season, including being in a neutral phase of the El Niño and La Niña cycle. Storms are generally stronger during the El Niño phenomenon, associated with warmer sea surface temperatures in the eastern tropical Pacific.
"We’re not expecting a strong La Niña or a strong El Niño," he said. "We’re in a longer-term period of reduced activity."
But another hit like Hurricane Iwa in 1982 or Hurricane Iniki in 1992 could cause billions of dollars in damage.
"Any tropical cyclone, just one that impacts the state … is going to be well-above normal for us in the state of Hawaii," Tanaka said.
New single-family houses and duplexes throughout the state could be required to build a "safe room" or install impact-resistant windows if they are in a high-wind area, depending on the design of the home, under the state building code.
The code was strengthened April 16to adopt provisions of the International Building Code’s 2006 edition.
Installing impact-resistant windows could cost about $10,000, experts say.
As an alternative to requiring impact-resistant windows, experts including structural engineers developed a proposal for a less costly "safe room" option. The cost of a safe room could range from $500 to $1,500.
The safe room option could allow a builder to use plywood instead of gypsum board along the walls of a room and also install impact-resistant windows in that room only or a covering that would make the window impact resistant.
Hurricane Iniki caused close to $3 billion in damage on Kauai, and more than 90 percent of all single-family and duplex residences lost substantial portions of their roofs, according a University of Colorado study and the National Weather Service.
