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

Tornadoes

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

Scale	Speed
	mph	kph
EF0	65–85	105–137
EF1	86–110	138–178
EF2	111–135	179–218
EF3	136–165	219–266
EF4	166–200	267–322
EF5	>200	>322

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

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