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Why the Midwest gets so many tornadoes

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It’s Hollywood’s most famous storm: a furious tornado uproots Dorothy and plops her in Oz. The howling winds transform her ordinary life. Like Dorothy, haven’t we all wished to be swept into a new adventure?

Beyond a movie set, of course, a tornado is simply dangerous, not magical. And you don’t have to live in bucolic, sepia-toned Kansas to be hit by one, either. Twisters touch down on every continent except Antarctica. But their prevalence in certain parts of the US is due not to fantasy, but simple airflow.

Warm, moist air wafts north from the Gulf, while the jet stream blows from west to east, gusting at 150 miles per hour, often over the central US. When these air masses overlap, the warm air rises, and like Dorothy’s house, it twists and turns when caught in the jet stream’s faster winds.

It’s a unique collision of windspeeds and directions. The result is an unstable atmosphere over the Great Plains, Midwest, and South. These conditions are perfect for forming supercells, the powerful thunderstorms that churn out tornadoes.

Perception plays a role as well. As the farmland scenes in The Wizard of Oz show, it’s easy to spot a tornado on a distant horizon. Tornadoes’ visibility across flat terrain—and the movie’s famous Kansas setting—causes most of us to believe that tornadoes only happen in the rural Midwest. But the collision of wind, and the landfall of tropical storms, means the South gets its share of twisters, too.

If you see a tornado, take proper safety measures. There are better ways to get to Oz: may I suggest the yellow-brick road?

A tornado begins to form in a sky with large, dark clouds

Conditions in the midwest are perfect for forming twisters. (QueenSunshine / flickr)

It’s Hollywood’s most famous storm: a furious tornado uproots Dorothy and plops her in Oz. The howling winds transform her ordinary life. Like Dorothy, haven’t we all wished to be swept into a new adventure?

Beyond a movie set, of course, a tornado is simply dangerous, not magical. And you don’t have to live in bucolic, sepia-toned Kansas to be hit by one, either. Twisters touch down on every continent except Antarctica. But their prevalence in certain parts of the US is due not to fantasy, but simple airflow.

Warm, moist air wafts north from the Gulf, while the jet stream blows from west to east, gusting at 150 miles per hour, often over the central US. When these air masses overlap, the warm air rises, and like Dorothy’s house, it twists and turns when caught in the jet stream’s faster winds.

It’s a unique collision of windspeeds and directions. The result is an unstable atmosphere over the Great Plains, Midwest, and South. These conditions are perfect for forming supercells, the powerful thunderstorms that churn out tornadoes.

Perception plays a role as well. As the farmland scenes in The Wizard of Oz show, it’s easy to spot a tornado on a distant horizon. Tornadoes’ visibility across flat terrain—and the movie’s famous Kansas setting—causes most of us to believe that tornadoes only happen in the rural Midwest. But the collision of wind, and the landfall of tropical storms, means the South gets its share of twisters, too.

If you see a tornado, take proper safety measures. There are better ways to get to Oz: may I suggest the yellow-brick road?

Reviewer: Cody Kirkpatrick, Indiana University

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