Here is an exercise to explore how the width of a tornado and the pressure difference between the surrounding air and the center of the funnel relate to the destructive wind damage a twister can produce.

All tornadoes, and most other severe local windstorms, are assigned a single number from the Fujita Scale according to the most intense damage caused by the storm. Using the slider controls below, you can adjust the funnel width and core pressure difference in the simulation, and then after clicking the "Go" button, observe the types of damage related to different Fujita Scale values.

Here is a breakdown of the Fujita (F) scale:

• F0 (weak): 40- 72 mph, light damage.
• F1 (weak): 73-112 mph, moderate damage.
• F2 (strong): 113-157 mph, considerable damage.
• F3 (strong): 158-206 mph, severe damage.
• F4 (violent): 207-260 mph, devastating damage.
• F5 (violent): 261-318 mph, (rare) incredible damage.

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.