What Causes a Tornado?

By Staff WriterLast Updated Apr 3, 2020 7:15:18 PM ET
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Strong warm updrafts carrying large amounts of moisture interacting with fast-moving cool, dry winds above cause tornadoes when the two air currents begin to swirl around each other and reorient toward the ground. The moist updraft is always of a type that forms large storm clouds as it ascends and the water vapor in it condenses.