These spinning columns of air can cause massive, if weirdly localized, destruction. Readers discover the conditions under which tornadoes form. The informative text explains what Tornado Alley is, and introduces the Enhanced Fujita scale, which is used to measure the destructiveness of these storms. The tornado that tore through Joplin, Missouri, in 2011 is featured in both a chapter and a two-page spread with statistics. There are chapters covering the ways scientists study tornadoes and the different kinds of tornadoes, too.