Tornadoes are a relatively rare event. Only a tiny percentage of thunderstorms ever go on to produce a tornado. No two twisters are alike—and some of those storms are truly bizarre. From twin ...

Severe thunderstorm and even tornado outbreaks can happen in December, even as most thoughts are about snow and cold. On Dec. 18, 1957, 68 years ago today, an outbreak of strong tornadoes tore through ...