NORMAN, Okla. -- As he sped along a stretch of rain-lashed highway, Gene Rhoden glanced over his shoulder and discovered that he was no longer chasing the tornado. The tornado was chasing him.
The lanky meteorologist and two friends deliberately drove into a squall near the town of Caney in southeast Oklahoma in March 1991, hoping to find a funnel cloud they suspected was spinning inside.
They cornered their quarry, a sinister blur of blue mist and churning debris a half-mile wide. But it turned on them, bearing down on Mr. Rhoden's Cutlass Supreme from the west at about 50 mph.
"We had to really just floor it," said Mr. Rhoden. The 100-to-150 mph vortex missed by a quarter-mile, shattering the windows of a van just behind them.
Each springtime, about 40 storm chasers begin prowling Oklahoma, the Texas panhandle and Kansas -- the heart of the Midwest's "Tornado Alley." They're hunting for nature's most violent storms, funnel clouds that can cut through fields, farms and neighborhoods like a power saw slices through a piece of plywood.
Some people chase for the thrill of it. Some are amateur weather enthusiasts. Some are hunting videotape for the evening news. But a few scientists at Norman's National Severe Storms Laboratory and the University of Oklahoma's School of Meteorology scramble after tornadoes to find out what makes them spin, so that they can predict the storms earlier and more accurately.
Tornado prediction is no trivial task. During the 1980s, tornadoes killed about 60 people a year in the United States and caused $1 billion in property damage annually.
While tornadoes rarely touch down in Maryland, they are not unknown. Eight small ones struck the state in August as part of Hurricane Andrew's parting shot at the East Coast.
So far, no chaser has been killed by a tornado. Still, racing after one is obviously riskier than boccie. What drives chasers,amateur and professional,to go looking for trouble?
"Some people like the adrenalin rush," shrugged Mr. Rhoden, a 27-year-old University of Oklahoma undergraduate. "It's exciting. It's entertaining. I'm more alive when I see storms."
Norman is probably the tornado capital of the planet. About 1,000 touch down in the United States each year, roughly 75 percent of those produced worldwide. And central Oklahoma sees more tornadoes per square mile than anyplace else.
Chasers spend weeks driving hundreds of miles, often in pouring rain and battering hail. They eat fast food, stay in cheap motels and spend thousands of dollars, all -- if they're lucky -- to glimpse a couple of funnel clouds roto-tilling the prairie.
About eight out of nine times, veteran chasers come up "busted," meaning they don't see any tornadoes. Most of those they do see are relatively small and short-lived.
But on rare occasions, lucky chasers will get to witness what some call "frog-stranglers" -- the mammoth storms that can churn up winds as high as 300 mph, last up to seven hours, travel as far as 200 miles and cut a furrow of mayhem up to 2 miles wide.
Some chasers are in it strictly for the thrills.
"I like to see the storm come at me," said James M. Leonard, who works part time chasing and reporting on storms for KWTV-TV in Oklahoma City. "I don't want to see it go by. I want to see it come at me, where it comes real close, where you're at the edge of its dust."
Mr. Leonard, 43, is a former public relations man for Florida Power & Light Co. who became a full-time storm chaser after the utility offered a buyout for employees two years ago. First he moved to Guam to watch typhoons, which is what hurricanes are called in the North Pacific.
"We had six between November 1991 and November 1992," he boasted.
He moved to Norman six months ago and over the past couple of months has put 20,000 miles on his car racing after funnel clouds.
Mr. Leonard first chased tornadoes in the early 1970s, during his vacations. It never gets stale, he said. The only thing that's changed over the past 20 years is that today he can talk about his obsession.
"Back in the early 1970s, if you admitted to chasing storms, they'd haul you off to a rubber room somewhere," he said.
Students at work
Howard B. Bluestein and a team of his graduate students at the University of Oklahoma are also out chasing this season. They're using an advanced portable Doppler radar system to try to study the variation among wind speeds in different parts of funnel clouds.
Until about 10 years ago, tornado research was limited to sending up balloons, taking ground measurements miles from the storm and making movies and photographs.
In the mid-1980s, researchers working out of the Severe Storms Laboratory here struggled over several seasons to drop a drum filled with weather instruments,aptly nicknamed "Toto," in the path of tornadoes,hoping it would get carried into a funnel cloud. That never happened.
Dr. Bluestein, a 43-year-old meteorologist and electrical engineer, has had more success with his radar. He's managed to make highly accurate measurements of wind speeds in tornadoes, and he hopes to map the speed and direction of winds at each point in the funnel cloud -- a key to understanding their complicated physics.
"The big prize is understanding exactly how a tornado forms," he said. Specifically, he said, researchers are puzzling over why some large, slowly rotating thunderstorms -- called mesocyclones -- produce the tightly coiled winds that become tornadoes while other mesocyclones do not.
Big tornadoes occur mostly in the spring, because that's when southern Tornado Alley becomes a battle ground for weather fronts, with dry air from Texas and the Southwest colliding with moist air from the Gulf of Mexico. This creates what is known as a "dryline," generally oriented along a southwest-to-northeast axis.
On a spring afternoon, after the sun has heated up the ground, warm moist air is pulled up along the dryline through the colder upper air. Sometimes this forms isolated cumulonimbus clouds or "supercells" -- towering structures with anvil-shaped tops that can reach twice as high as Mount Everest. Rain, propelled forward by upper-atmosphere winds, will often fall in front of the slowly rotating supercell's ominous black underbelly, which may sprawl over an area of 1,200 square miles.
Knowing where to look
When conditions are just right, a spinning, pedestal-shaped shaft -- called a wall cloud -- will lower out of the supercell, usually southwest of the storm's leading curtain of rain.
Chasers watch this pedestal, because that's where tornadoes usually start -- snaking to the ground in a variety of shapes and shades ranging from slender, translucent pencils to menacing, blue-black bowls.
With advances in forecasting and communications, death rates from tornadoes have been dropping steadily since about World War I. In the 1960s, tornadoes might be predicted up to four minutes in advance. Today, forecasters using the National Weather Service's new NEXRAD radar data routinely issue tornado warnings up to 20 minutes in advance.
Dr. Charles A. Doswell III, a research meteorologist at the Severe Storms Laboratory, says scientific chasing, advanced computer models and modern weather radar "have revolutionized our understanding of storms."
He added: "I'm confident we've saved lives as a result of what we've done."
When he's not chasing, Mr. Rhoden, a part-time employee with the Severe Storm Laboratory, sometimes studies the pattern of storm damage -- in part to correlate what happened in the tornado's path with what radar pictures show.
Tracking the damage
Last month he surveyed the town of Catoosa, north of Tulsa, in the wake of a 160-mph tornado that tossed cars and trucks around an interstate highway, plowed through about 20 houses in one development and reduced 60 mobile homes to splintered plywood. Seven people died, and another 95 were injured.
Typically, Mr. Rhoden said, many single-family, ranch-style homes with attached garages are ripe targets for tornado-force winds.
"The garage door blows in, the back walls blow out, and the roof comes up," he said. "The house has been blown up like a balloon."
Mobile homes are even more dangerous, because they can become airborne. But the most perilous spot to ride out a tornado is in a car, he said, which can get picked up and dribbled down a highway like a basketball.
Many veteran tornado chasers say the storms don't scare them. But they're terrified by what Dr. Doswell calls "chase cowboys," people with little interest in weather drawn by the danger and publicity. They drive down wet roads at speeds from 85 mph to 100 mph, he said, blow past stop signs, drive around police barricades and skid to a stop in the middle of the road to watch.
TV crews in the way
Over the past two years, television news teams have become more of a nuisance as they compete for hair-raising tornado footage. All three of Oklahoma City's network affiliates deploy squads of spotters and camera crews.
Veteran chasers lament the new popularity of their once-lonely obsession. But Dr. Bluestein is more philosophical.
"If you think of storm chasing as a sport, then 10 years ago it was a lot more fun," he shrugged. "If you're talking about going out and doing research, the instruments are much better. I'm sort of halfway in between. I got out for the research, but I also enjoy the view."