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How do tornadoes form?

How do tornadoes form?

Learn how tornadoes form, as explained by John P. Rafferty, earth and life sciences editor of Encyclopædia Britannica.
Encyclopædia Britannica, Inc.
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News •

Turkey tornado kills 4 at Antalya construction site • Oct. 27, 2026, 2:39 PM ET (The Weather Channel)
'Zeus was angry:' Arizona surveys damage from at least 3 rare tornadoes • Oct. 22, 2026, 4:46 PM ET (AP)

Transcript

A tornado is a weather phenomenon that extends from a strong thunderstorm. Tornadoes are formed when a layer of cool dry air sits on top of a layer of warm moist air at the surface. You have a very warm day that heats up the air at the surface--maybe over a large region of a crop--and the water in that crop saturates the air and wants to move upward. So, long about the mid-afternoon when temperatures are the highest of the day, that upward movement is very very rapid. And that intensifies thunderstorms and could bring about the possibility of tornadoes.
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