NOAA
Noaa: Tornadoes, Nature's Most Violent Storms
This page, put out by the National Weather Service, thoroughly explains the causes and types of tornadoes. Tornado safety is covered in the form of warning signs and what you can do to stay safe both in school and at home. The full...
University of Illinois
University of Illinois: Hunt for the Supertwister
Find out how computer generated tornado models are being used to understand the formation of the rare super twisters. You can view a video of the computer model and view the same footage in a slide format which has detailed explanations.