Using data from NOAA, exported as a heap of images via Visual Fusion, the Tornado Tracks map has been smooshed through the animation ringer to illustrate 61 years of tornado activity through time.
Pro tip: check out 1974 and 2011.
Pro tip: check out the seasonal march north every year, and try out the HD option for full-screen crispiness.
Adam Hill, current Freaky Friday champion, made the interactive version of Tornado Tracks. Deb Davis honed its towering heap of exported map images into these animations.
Set of related tornado tracks infographics: