‘Storm-Chasers’ Brace for Twister Season, Say Studies Are Cutting Death Toll

NORMAN, Okla.--Probably 40 times before, Robert Davies-Jones has watched tornadoes spin from thunderstorms and churn across the prairies, but each time it’s a new thrill.

“It’s very exciting,” he said. “As long as they stay out in the open country and don’t do much damage.”

But he also knows the violent swirling columns that combine the beauty, mystery and raw power of nature don’t always stay in the fields.

“I’ve been on a lot of damage surveys,” he said. “It’s kind of depressing.”

Each year in the United States tornadoes kill more than 100 people and inflict millions of dollars damage. From 1980 through 1984, more than 4,500 tornadoes and 273 deaths were reported.

Deadliest Twister in U.S. History

The deadliest tornado in U.S. history killed 689 people in Missouri, Illinois and Indiana in 1925. Probably the costliest tornado in the U.S. ripped through Wichita Falls, Tex., in 1979, doing almost $800 million damage and killing 45.

For 10 years Davies-Jones has headed a group of “storm-chasers” who try to get as close as possible to tornadoes to study them. More knowledge, it is hoped, will help reduce deaths. Davies-Jones says it apparently has helped, with annual tornado death rates decreasing from about 200 per year before the 1950s to about 100 per year now.

The native of Leicester, England, is a scientist at the National Severe Storms Laboratory in Norman, Okla., the government’s key center for probing the darker side of weather.

“I’ve never been in a killer tornado,” he said. “I’ve never seen anybody injured. I think if I did it would kind of turn my stomach.

But Davies-Jones has a deep respect for the force unleashed in a tornado. He’s seen cars flung 200 yards and frames of mobile homes curled around trees.

With the approach of spring comes another tornado season, meaning Davies-Jones and his crew prepare for 10 weeks of being on call for the right combinations of weather for the powerful funnels to form.

“It’s sort of my spring occupation,” he says.

The tornado season begins earlier in the far southern regions of the country and follows the jet stream northward into mid-summer. In Oklahoma the season starts in March and lasts into June.

However, tornadoes can occur any time of the year and anywhere in the country, from Hawaii to Florida. But Oklahoma and northern Texas are the hotbeds of activity.

The menacing thunderstorms and “wall clouds” that are breeding grounds for tornadoes grow along the “dry line” between southern air carrying Gulf moisture and dry, cooler air from the west.

That’s a major reason the NSSL was built in “tornado alley” in 1964.

Using computers, radars, mathematical models and other tools, researchers believe they have unraveled the mysteries of many weather phenomena. But for the most part the tornado remains an enigma.

For instance, experts have found a tornado can be anywhere from several yards to a mile wide at the base. It can stay on the ground for minutes or up to three hours, grinding a “damage path” only yards long or spanning hundreds of miles through several states.

Larger ones many times appear to be made up of several funnels or “vortices” that can weave among themselves along the path of destruction. Winds in a small tornado can be 125 m.p.h., while they can reach 275 m.p.h. in a large one.

But unanswered are questions such as: Exactly how and where do tornadoes form inside a storm? What kind of pressure drop does it carry inside? And, what is the temperature inside a tornado?

“We know a lot about the mesocyclone (the tornado-producing storm), but we don’t really know the details of how the tornado forms inside the mesocyclone,” said Davies-Jones. “This is the missing link.”

One major accomplishment of NSSL research has been the development of Doppler weather radar, a system that could revolutionize tracking and analysis of severe storms.

The radar is named for the “Doppler effect,” the fact that sound or other energy waves coming from an object will show a shift if the source is moving. For instance, a train whistle moving toward an observer will be of a higher pitch, and one moving away will shift to a lower pitch.

Old Systems Limited to Rainfall

Thus, Doppler radar is able to detect the direction and speed of rain, clouds and even wind. The old radar systems installed in the late 1950s can only show rainfall.

With Doppler, “you can also get an idea of the motion of the air in the system,” he said. “You can get . . . what the wind speed is inside the storms and you get an idea of the turbulence.”

By the early 1990s, a network of about 100 Doppler systems will be in place.

“I think the main benefit we will realize from Doppler will be improved service in warnings,” said Ed Ferguson, deputy director of the National Severe Storms Forecast Center in Kansas City, Mo.

The center is responsible for issuing tornado watches for the entire country, while 53 National Weather Service offices around the country issue tornado warnings.

Ferguson said Doppler would allow warnings to be issued while tornadoes are being formed, as much as 20 minutes before they strike.

“That in itself would be a tremendous help and improvement in the warning program,” he said. “As far as we’re concerned, our main benefit would come from research . . . into better understanding the physics of tornadic storms.

“Right now, we don’t know much about them.”

Some of the myths about tornadoes can save your life; others will kill you, weather experts say.

But those experts guided by high power technology are nevertheless hesitant to debunk all the old wives tales and bizarre superstitions about tornadoes.

Fort Worth meteorologist Al Moller of the National Weather Service has studied some of the old superstitions and says many are founded on astute observations.

For instant, one old wives tale warns that tornadoes drop from murky clouds that drift toward the ground, and that they are accompanied by short claps of thunder and blinking red or pastel lightning streaks rather than common long bolts.

“There’s a lot of truth to this,” said Moller. “I can get very complex about this in a hurry, basically because we don’t understand it. But since a tornado develops immediately southwest of the rain in a thunderstorm system, lightning bolts striking the ground will appear very short and sometimes even look like they’re repeating themselves. In some tornadic storms at night, lightning is pastel--blue and pink and green.

“In fact, it’s been suggested the tornado itself acts as a preferred electric connection to the ground. Some funnels glow.”

He says, though, there’s no basis to the folk remedy of cutting the wind with an ax or scythe to break its force.

“I put no stock whatever in this legend of ‘cutting the storm,’ ” Moller said. “If it’s the right kind of storm and it’s coming your way, your standing out in the yard swinging an ax at it isn’t going to faze it one bit.”

It’s also false that a tornado won’t cross water.

“In April, 1970, a very powerful tornado developed south of Abilene (Texas), moved directly across a lake as a waterspout, smashed into a trailer park and killed a number of people,” he said. “A tornado doesn’t care what’s underneath it.”

Nor is it true that tornadoes strike from dead calms.

“As a matter of fact, tornadoes usually occur when surface winds are hitting 20 to 30 m.p.h.,” he said. “This story keeps making the rounds because sometimes just before a tornado arrives, the horizontal winds that have been blowing are sucked into the updraft and become vertically rising air, so they’re not noticeable.”

It’s generally true that tornadoes travel in a beeline from the southwest to the northeast and spin counterclockwise, he said, but there are enough exceptions to kink the statistics.

“About one out of four tornadoes will move from the northwest to the southeast and a few mavericks will spin in from the east, but most of those coming from the east are associated with hurricanes,” he said. “Late in its life cycle, a tornado’s tracks will sometimes curve, and we also have records of tornadoes that have made U-turns or complete loops.”

Tornadoes, which can pack winds of more than 200 m.p.h., occasionally seem to sport a macabre humor.

Weather historian Barbara Tufty recounts the tale of a woman sucked through a window in a June 10, 1958, tornado in El Dorado, Kan., spun through the air and set down beside a phonograph record titled “Stormy Weather.”

Other tornadoes reportedly have sucked corks out of wine bottles, plucked live chickens and driven straws into trees.

“Things like that have happened, but not because tornadoes have a sense of humor,” Moller said. “All the tornadoes I’ve seen have been kind of mean. For every person who’s set down gently, I’ve seen many, many maimed or killed. In most cases, the people carried aloft don’t come back in very good shape.”

The story about straws being driven into trees and fence posts is true, “but what’s really happening is that the wind force is so strong the wood fibers literally split across, allowing the straw to enter, then slam shut.”

Tornadoes seem sometimes to develop a fondness for particular areas, giving the lie to the wishful belief that they will not hit the same place twice.

“One man in Wichita Falls (Texas) lost his home in 1958 to a tornado, then lost it again in 1964 to another tornado, then gave up and moved from his neighborhood near the Red River to the south part of town, where a tornado in 1979 again destroyed his house,” Moller said.

He said weather experts no longer advise people to open the doors and windows of their houses to keep them from exploding in the vacuum a tornado supposedly creates.

Brute Wind Force Blamed

“We preached this a long time, but engineering studies have prompted us to change our minds,” he said. “It’s the brute wind force, not the vacuum, that knmcks a house flat. In fact, flying glass has cut up quite a few people rushing to open their windows at the last minute.”

The Indian legend that tornadoes will not strike a community on the fork of a riter has given many people a false sense of security, Moller said.

“Waco (Texas) is at the junction of the Bosque and the Brazos riverq, and the tornado that went through that town in 1953 killed 114 people,” he said. “Most of the tornadoes that have struck Wichita Falls have followed the path of the Red River.”

Moller said it is true that pets sometimes seem to know what’s coming before their masters. “I’ve seen animals get wild and woolly when violent storms are about to strike. They may be sensing rapid pressure changes.”

But, he says, there are no guarantees.

“The best animal for predicting tornadoes still is a well-trained human being,” he said.