Storm Chasers Probe The Mysteries Of Southern Tornadoes
A team of meteorologists recently wrapped up the first phase of an unprecedented project to study tornadoes in the South. WUOT’s Brandon Hollingsworth reports the project’s results could change what meteorologists thought they knew about severe weather.
Twenty years ago this summer, the movie Twister hit theaters. The blockbuster undoubtedly influenced the way its viewers thought about storm chasing and tornadoes. Its special effects tossed barns, tractors and cows at the audience, and showed storm chasers doing some pretty stupid things in the name of science. So it’s not what you’d call super accurate.
But a group of real storm chasers is now taking stock of a pioneering study designed to root out some of the mysteries of tornadoes in the South. The National Severe Storms Laboratory (NSSL)'s Project VORTEX-Southeast put weather instruments and people in parts of Alabama and Tennessee to see what makes twisters here so different from their Midwestern counterparts. And so far, no flying cows.
“You know, we’ve done a lot of research – probably about thirty years’ worth – on the Great Plains," says NSSL's Erik Rasmussen. He leads the VORTEX-SE effort. “We have a decent idea of how these storms behave, and when to expect tornadoes, and even how strong we expect the tornadoes to be. But when it comes to the Southeastern U.S., things are really quite different.”
Already Rasmussen and the VORTEX team have homed in on two major factors: humidity and wind. Pretend for a moment that a severe thunderstorm is a skyscraper, maybe a hundred stories tall. Rasmussen says the crucial activity seems to be happening on the very lowest floor, right near the ground. If weather forecasters can tease out a predictable pattern in that layer, they might have a key to understanding the way severe storms behave.
“There’s probably all sorts of clues that are happening maybe twenty or thirty minutes back in time, ahead of the formation of the tornado, that could give us a whole lot more confidence in whether a tornado’s going form or not," says Rasmussen.
VORTEX-Southeast is also studying the way humans behave when severe weather hits. University of Tennessee climatologist Kelsey Ellis is examining that side.
"I’m very interested in knowing how people perceive the climatology of tornadoes here. We get them at night. We get them during the winter months, which is not what you expect in places like Tornado Alley," she says. "And so we’re wondering if issues of people not understanding their climatology may not have them prepared for these events when they happen.”
VORTEX-Southeast works with three distinct groups of people: The public, meteorologists who study weather and meteorologists who forecast weather, like Ken Weathers of WATE, Knoxville’s ABC affiliate.
"You want people not so much to be scared, but you want that communication aspect, and that education aspect," he says. "What can we do to help better educate our audience?”
Weathers hopes the data from VORTEX-Southeast will help him communicate the dangers of severe weather to his viewers.
“Maybe [we can] break the misconception that tornadoes don’t happen here...that mountains protect you - they don’t. That rivers protect you - they don’t. That lakes protect you - they don’t. You know, common misconceptions that I’ve heard that I have to debunk every time I go out and give talks.”
VORTEX-Southeast’s first study season wrapped up in May. But Erik Rasmussen and his team will be back next spring to pick up right where they left off. Rasmussen says they’ve already learned a lot about tornadoes and how they’re affected by unique conditions in the South. But no smoking gun…yet.
"Toward the 1990s I thought, ‘Yeah, we probably just about have this nailed, and it didn’t turn out to be that way. So it’s kinda hard to say how much further we have to go,” Rasmussen says.
In the meantime, the VORTEX team is spending the summer refining its theories, with the first round of conclusions expected to be published this fall.