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Name: J. F. W.
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 9/22/2004

How large is the eye of the tornado? How small is the base and the top. I realize that depends on the size of the tornado, but what is the average size of the eye?

J. F. W.,

Tornados range in size from several feet across to as much as a half mile. Many tornados, especially the larger ones, are nearly a cylinder and do not change much in diameter with height. Small, young or old tornados can be more conical as support for the base of the tornado is weaker. Some even become "rope-like" as they are dying, with the tornado bending as a result of different wind speeds at different heights.

The "eye" of the tornado is not much smaller than the tornado vortex (the rotating air) itself. There really is no easy way to say what the average diameter of the eye or the vortex is, since they can range in size so drastically. But an average tornado may be about 200 feet in diameter. What you see on the outside of the tornado is the debris (dust, plants, building parts, etc.) that are being thrown around by the vortex, making the tornado look wider than the vortex really is.

David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory

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