tornado chasers!

Chasing Tornadoes, Tornado Alley, Storm Chasing - National Geographic

This article is somewhat long but I found it fascinating to read. It explains how stormchasers set up things called turtles that can measure the different aspects of a tornado. It tells a couple of stories of how people have escaped quickly and survived bad storms and how one man was sucked into a tornado and was still living. The turtles, also known as probes are so strong that they can stay in place when tornado winds go past them. They are able to catch pretty accurate measurments of the tornado winds, shape and size.