Physical Science 101

Watch the video Tornado!.

This video will not be shown during classtime. The outline provided below is simply a list of the major topics covered in the video and is not intended to be a substitute for viewing the video. The entire video may also be viewed on YouTube at the following link: NOVA: Tornado!.

I. Tornado Alley
II. Tornado Characteristics and Formation
III. Tornado Chasing
IV. Tornado Experiments
V. Barneveld, Wisconsin


Rapidly rotating winds around a small area of intense low pressure.
Commonly known as twisters or cyclones.

Basic Stats

Diameter: 100 to 600 m average - range few meters to 1600 m
Movement: SW to NE (North America)
Ground Speed: 35-75 kph average
Duration: few minutes to hours
Path Length: 7 km average
Rotation: counterclockwise and clockwise (rare) in the N. Hemisphere

Enhanced Fujita Scale

Tornado Categories based on wind speeds


Stages of Development

1) Dust-Whirl Stage:
2) Organizing Stage:
3) Mature Stage:
4) Shrinking Stage:
5) Decay Stage:

Tornado Formation

Formation along the Polar Front
Formation along the Dry Line
Tornado Alley