Skip navigationTwister: The Tornado Story
 

1. Story map
2. Tornado disaster
3. Interactive twister4. Energetic wind
5. A safe house
6. Twister-in-a-bottle
The Fujita scale of tornado violence. An F-5 tornado makes the strongest winds on Earth; Doppler radar clocked one tornado at 318 mph. (In the Fujita scale, wind speed is not measured directly but rather estimated from the amount of damage. Tornado width is estimated by the path of destruction -- which can be up to one mile wide).
Note: Mac OS 9 users: works best with Internet Explorer.

  The size of a twister
Can you control the intensity of this twister by changing the diameter and/or the core pressure difference?

This applet and illustrations are Copyright(C) 2003 by Tom Whittaker, S.V. Medaris, and Steve Ackerman. The Motion-W® and Bucky Badger® logos are Trademarks of the University of Wisconsin-Madison.

Fujita damage scale chartA tornado that's 500 meters in diameter looks a lot more ominous than the average twister, which is "only" 150 meters across. But tornado size is not related to wind speed, or to damage intensity. Instead, wind speed increases along with the difference between atmospheric pressure inside the funnel, and the pressure outside it (the core pressure difference). The larger the difference in atmospheric pressure between the core and the surrounding air, the faster the winds.

But at a given wind speed, a larger tornado will do more total damage.

Where does all this energy come from, anyway?

 
 
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The Why Files
 

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