To meteorologists, a tornado is a violently rotating column of air, which is connected to a cumuliform cloud at one end and the ground at the other. They're usually visible as a funnel. To the rest of us, they're just frightening. Now that it's April, we're at the beginning of the season in which tornadoes appear most frequently, which starts first in the Southeast and gradually spreads westward and northward. ￼
Scientists still can't completely explain why tornadoes form. The classic explanation is that warm, moist air from the Gulf of Mexico meets cold Canadian air and dry air from the Rockies. But as the National Oceanic and Atmospheric Administration's tornado FAQ notes, most thunderstorms that form under those conditions don't form tornadoes. We do know that the most destructive and deadly tornadoes occur from supercells -- which are rotating thunderstorms with a well-defined radar circulation called a mesocyclone.
Here are some surprising and intriguing facts about the fearsome funnels.
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