It's one of the most awesome sights in nature, a tornado ripping across the Great Plains.
"It's amazing how addicting storm chasing is," Hill said.
Customers with Hill's silver lining tours pay up to three thousand dollars for a ten-day trip aboard one of these vans.
They come from all over. There's Michael Pare, for instance, an I.T. manager from Maryland. Mark Rosengarten, a science teacher from New York. And Bob Seifert, a mortgage broker from California. This is his twelfth trip. He's such a tornado fan that he's got one tattooed on his leg!
"21 tornados altogether we've seen," Seifert said.
There's also a professional photographer from the Netherlands, a teacher from Germany, and a computer-network engineer from Northern Ireland.
Driving 600 miles a day is perfectly common on one of these tours, often through pounding rain and lightning.
The tour guides use Doppler radar and other high-tech weather gear to pinpoint storms. They stress they put passengers' safety first.
When it all comes together, the result is amazing.
Driving hundreds of miles every day with a bunch of strangers is not everyone's idea of a vacation. And all those miles can be pretty grueling. But, Bob Seifert sums up the attraction this way:
"This is my passion. It's just awe-inspiring."