为什么要追逐龙卷风？

LINDA WERTHEIMER, HOST: Oklahoma officials now say that 18 people died in last week's storms and floods. Three of them were tornado researchers, professional storm chasers, who appeared on a Discovery Channel reality show on the subject.

Josh Wurman heads the Center for Severe Weather Research. We first heard from him on this program after the massive tornado that hit Moore, Oklahoma last month. He also appears in that Discovery Channel show and, as it happens, he too was chasing the deadly storm near El Reno that took his colleagues' lives. But Wurman decided to turn back. We called him to find out why.

JOSH WURMAN: We saw a couple of things that made us think we needed to get out of there for safety, one was that the storm was becoming completely wrapped in rain. So the tornado was impossible to see visually. And also, there was a second tornado spinning in the opposite direction about three miles to the south of the first tornado. So we found ourselves between two different tornadoes, and the situation was becoming uNPRedictable enough that I thought my team was at too much risk.

We took the data we had and we basically retreated east to try to regroup and intercept the storm closer to Oklahoma City.

WERTHEIMER: Well, now reading about that storm and about the deaths of your colleagues, I think anyone would wonder why take such terrible risks. Is there that much value in doing it, that much scientific value?

WURMAN: Storm chasers have a wide variety of motivations. And many storm chasers, of course, are thrill-seeking. Scientists like myself, we're really not getting much thrill out of it. We have very particular missions. They're aimed at answering important questions about tornado science. And these questions are aimed at enabling forecasts to get better. People die in tornados, and if we can make the forecast better, then fewer people will die.

WERTHEIMER: Do you have any idea why your colleagues did not make the decision that you made, to try to get out of its way?

WURMAN: Tim Samaras is known as a very responsible, very experienced, very skilled storm chaser. And I'm surprised. He would be one of the last people I would expect to have been caught up in a storm like this, because he knew when to be cautious. We don't know the details of exactly what happened. So we don't know if it was related to a decision or something that was really truly uNPRedictable.

WERTHEIMER: What does this do to the community of storm chasers to have a crew like Mr. Samaras' lost in a storm?

WURMAN: I think the storm-chasing community and the research community is still absorbing the loss of Tim Samaras, his son and his colleague; trying to really understand whether this reflects on our techniques - on whether or not this activity, the way it's been done in the last few years, the way it's evolving - can continue to be safe.

My team, we've never had an injury. We've never had a vehicle destroyed. But still, my team is going to be meeting and reevaluating its procedures. There's really no data set which is worth being injured for or dying for.

WERTHEIMER: Mr. Wurman, thank you very much.

WURMAN: Good talking to you.

WERTHEIMER: Josh Wurman of the Center for Severe Weather Research in Boulder, Colorado.

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