Every six hours until Hurricane Flossie passes Hawai'i, a crew of hurricane hunters will fly out from Hickam Air Force Base and venture into the eye of the storm.

Their mission: to gather real-time data about the storm that's critical for the accurate prediction of the storm's strength, location and expected path.

The U.S. Air Force unit, flying four WC-130 hurricane tracker planes, was dispatched from Mississippi on Sunday and began flying six-hour missions through the storm. The third flight into the storm took off from Hickam at about noon yesterday.

Lt. Col John Fox, with the Air Force Reserve 53rd Weather Reconnaissance Squadron, navigated the first flight into the storm Sunday and has flown through more than 100 hurricanes and other storms.

Fox said yesterday if Flossie were an ice cream flavor, it'd be a "vanilla hurricane."

"It's a fairly compact storm. You don't want a big wide eye, like when Katrina hit us in Biloxi," he said in a briefing with media at the base yesterday. "It's pretty much a vanilla hurricane. ... That could change."

Indeed, the storm appeared to change in a variety of ways in the six hours between Fox's mission and that of Lt. Col. Kurt Nelson and his crew, which returned to Hickam shortly after 11:30 a.m. yesterday.

Fox's crew observed an eye of 16 miles, but that appeared to have increased to 25 miles yesterday morning. Winds also had picked up from 125 mph to about 144 mph, Nelson said.

'ROLLER COASTER RIDE'

Nelson said he encountered several violent thunderstorms as his crew penetrated the storm's eye wall.

Flying in the area immediately outside the calm eye is "like a roller coaster ride," he said.

A crew of about 70 personnel, which includes 22 flight crew members and other support staff from the 403rd Wing based at Keesler Air Force Base in Biloxi, Miss., will alternate flights into the eye of Flossie throughout its lifetime.

The hurricane hunters play a critical role in helping forecast storms. The instruments aboard the flights gather storm measurements that are sent to the National Hurricane Center, giving forecasters the latest information to improve storm predictions. The data they gather can help improve the accuracy of predictions by 15 percent to 20 percent, Nelson said.

NOTHING NOTEWORTHY

Yesterday's flights were particularly significant, serving as an early use of new measurement technology called the Stepped-Frequency Microwave Radiometer, known commonly as a "smurf."

The smurf, mounted to the aircraft's wing, uses radiation that can penetrate the storm clouds to measure wind strength at the ocean surface, essentially measuring what would be experienced if the storm hit land.

Fox said there wasn't anything particularly memorable about Flossie, which he says is a good thing.

"When you remember something about a storm, it's usually something bad," he said.

It certainly couldn't compare to Fox's flight through Hurricane Katrina two years ago.

"It'd be like comparing (Steve) Urkel (a nerdy character on the 1990s sitcom "Family Matters") to Mike Tyson," he said.

But he was quick to point out the unpredictable nature of tropical storms.

"I knew (Katrina) was going to be very, very bad ... but no one could have predicted that kind of destruction," he said.

Despite the danger of his job, Fox said he's flown thousands of hours through many storms and likened the experience to "spending six hours in a car wash."

Not to mention that most of the hurricane hunters are "weather nuts," he said.

"It's like me asking how was your drive to work," he said.

Reach Loren Moreno at lmoreno@honoluluadvertiser.com.