On TV: Watch Tornado Intercept premiering Sunday, December 18 at 8 p.m. ET/PT on the National Geographic Channel.
Documentary filmmaker Sean Casey recently teamed up with meteorologist Josh Wurman to push twister science further than ever before.
With Casey driving his steel-plated tornado intercept vehicle into a raging twister, Wurman and his caravan of Doppler trucks followed close by to collect data from the tornado's most destructive—and least understood—zone: the lower 30 feet (9 meters).
National Geographic News spoke with Wurman on the phone from Boulder, Colorado, where he directs the Center for Severe Weather Research. He receives funding for his research from the National Science Foundation and the National Geographic Society.
I'm sure you've been asked this many times, but … are you nuts?
We're doing a very carefully choreographed deployment around the tornado, using mobile radar that can scan through tornadoes every few seconds. We know exactly where the tornado is, how big it is, how strong it is, how fast it's moving.
We have quantitative information about many parameters in the tornado and can do things safely that may appear to be on the edge if you didn't have that kind of information.
What kind of information about the tornadoes do you get from the radar?
We have intercepted over a hundred tornadoes with radar. Our goal is to get as complete a picture of the tornado as we can. The radar enables us to take multiple slices through the tornado every ten seconds to a minute, and make 3-D images of the outside and the inside of the tornado.
In addition, what we want to do is measure the thermodynamic properties around the tornado. It turns out that a lot of the physics that's driving why the tornado has certain wind speeds, why it's large, or why it's getting stronger is driven by the thermodynamics in the air.
What's the range of the radar? How close to the tornado you have to get?
The [radar] can see out a hundred miles or more. But we need to get much closer—usually anywhere from half a mile to three miles [one to five kilometers] away—where you get much finer detail.
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