The limitation is that we can't see very close to the ground. Inevitably there are small hills, trees, bushes, and fences in the way. This means we're not very effective with the radar below 50 feet [15 meters].
And that's where the tornado intercept vehicle, or TIV, comes in? Describe it for us.
It's a Ford truck with its body taken off. It's been armored with 8,000 pounds [3,630 kilograms] of steel plating. It's very difficult to lift because it's low to the ground. It's aesthetically ugly, but functionally it's beautiful. What it lets us do is extend observations into the tornado by driving the truck into [the twister].
And you get information that you otherwise wouldn't be able to get?
We can measure what's actually happening on the ground or very close to the ground in a tornado. That's a critical region for us to understand, both from a scientific point of view and from an engineering point of view.
[For example], there are different numbers flying around for how fast tornado wind speeds are. I've measured with the radar winds up to 300 miles an hour [483 kilometers an hour], but wind engineers with computer simulations and lab experiments know that you could produce the worst possible damage that has ever been observed with winds that are only about 200 miles per hour [322 kilometers an hour]. What's happening is that the winds are a little bit less at the ground level than they are at 50 or 100 feet [15 or 30 meters].
You used the TIV to collect data on a tornado this year. Tell me about that.
It was a moderately strong tornado … that went over open country near Jayton, Texas. The TIV basically drove right up there, but the tornado didn't cooperate and kind of dodged around the road. The center missed the TIV by about a hundred meters. They were at the edge of the tornado's flow.
It was really groundbreaking for us, because we were able to measure wind speeds about 50 feet [15 meters] over the TIV and at 10 feet [3 meters] above the ground.
How confident are you that this vehicle can withstand the power of a tornado?
The key is to do this with the radar. What we provide the TIV is critical safety information. We can tell them every ten seconds how strong those winds are. Are they getting stronger or are they getting weaker? How close to the center of the tornado can you go?
We're able to say, That tornado has 120-meter-a-second [268-mile-an-hour] winds, it's scouring everything in its past, and you really don't want to go to the heart of it because it can hurt you. No rational explorer takes undue risks. Successful scientific exploration involves living to repeat and confirm discoveries.
How could this information help engineers to build more storm-resistant buildings, for example.
There are basic questions that we don't know the answers to right now. For example, What's worse: a 300-mile-an-hour [483-kilometer-an-hour] wind for a second or a 200-mile-an-hour [322-kilometer-an-hour] wind for a minute? You could engineer different kinds of structures to withstand those different kinds of things.
What about forecasting tornadoes?
There are thousands of severe, rotating super-cellular thunderstorms every year. Probably only a quarter of them produce tornadoes, and we don't have a good ability to distinguish which ones will and which ones won't.
The other thing we need to be able to do in areas where tornadoes do occur is to warn earlier and provide tornado intensity forecasts. This is important because if I knew an F0 tornado was coming, I might just get into the bathtub.
[Scientists rate tornado intensity after the fact using the Fujita Scale, a scale of zero through five that measures how much damage a storm does when it hits a man-made structure.]
But if I'm told with half an hour's warning that an F5 is coming, I might take the risky action of getting into my car and hoping my car isn't going to get stuck in the tornado, because I know my bathroom is not going to survive an F5.
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