What Causes a Tornado Transcript

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What Causes a Tornado?
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The swirling, funnel-shaped winds of a tornado are easily recognizable—and they can be
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very dangerous.
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But what causes these unique and violent weather phenomena?
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Tornados usually begin with a thunderstorm.
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But not just any thunderstorm—a specific kind of rotating thunderstorm called a supercell.
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They can bring damaging hail, strong winds, lightning and flash floods.
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Supercells form when air becomes very unstable and wind speed and direction are different
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at different altitudes.
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This condition is called wind shear.
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Wind shear is common in the formation of most thunderstorms.
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But when wind at ground level is blowing in one direction…
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…and wind higher up in the atmosphere blows in a different direction
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…it can cause a horizontal tube of air to form.
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In a thunderstorm, warm air rises up within the storm.
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This is called an updraft.
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An updraft can turn a horizontal rotating tube of air into a vertical one.
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When this happens, the whole storm begins rotating, creating a supercell.
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Some supercells form a funnel cloud.
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And if that funnel cloud extends to the ground, it is called a tornado.
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Tornados can produce winds up to 300 miles per hour at the surface, making them dangerous
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to people and property.
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As a tornado moves along the ground, its strong winds begin to pick up debris, too.
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In fact, flying debris is usually what causes the most damage in a storm.
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Thankfully, meteorologists are keeping an eye on your local weather.
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They will try to give you a heads up if a tornado is likely to form in your area.
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They combine wind and temperature readings form the ground with information from satellites
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to determine if your local weather has the right conditions for a tornado.
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For example, NOAA’s GOES-East satellite captures this video of an isolated supercell
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storm in Texas.
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The different colors represent different cloud top temperatures in the storm.
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Colder temperatures represent higher cloud tops, which often mean stronger storms.
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So, if you see a tornado watch or warning in your area, look for updates and get to
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safety as soon as possible.
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And know that NOAAs GOES-R series satellites will still be keeping a close eye on things
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from orbit.
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Find out more about extreme weather at NOAA SciJInks!