Social Sciences and History / Unit 10 SSH 0936 short lesson, about 20 seconds
Thunderstorm, Tornado, Tropical Cyclone
Captions available
The idea
A thunderstorm needs warm, moist, unstable air lifted by convection, convergence, orographic uplift or a front. A tornado descends from a supercell's mesocyclone. A tropical cyclone, hurricane, typhoon or cyclone by basin, has winds over seventy-four miles an hour and an eyewall.
In practice
Forty thousand thunderstorms a day worldwide.
Where people slip
About seventy-five percent of tornadoes occur in the United States.
Your place on the trail
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Unlocks
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