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15 Cards in this Set
- Front
- Back
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What is a thunderstorm?
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A thunderstorm is a small, intense weather system that produces strong winds, heavy rain, lightning, and thunder.
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Where can thunderstorms occur?
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They can occur along cold fronts. Warm, moist air rises rapidly in an unstable atmosphere.
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How are thunderstorms produced?
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The air near the Earth's surface must be warm and moist, and the atmosphere must be unstable. This happens when the surrounding air is colder than the rising air mass.
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What is lightning?
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It is a large electrical discharge that occurs between two oppositely charged surfaces.
ex. Walking on carpet and feeling a "shock" when you touch someone. |
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What is thunder?
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This is the sound that results from the rapid expansion of air along the lightning strike.
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What can severe thunderstorms produce?
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They can produce high winds, hail, flash floods, and tornadoes. Lightning is responsible for many forest fires each year and has killed many people.
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What is a tornado?
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It is a small rotating column of air that has high speed winds and low central pressure and tat touches the ground.
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How does a tornado start out?
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It starts as a funnel cloud that pokes through the bottom of a cumulonimbus cloud and hangs in the air. When it makes contact with the Earth's surface, it is a tornado.
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Where do the most tornadoes occur in the world?
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About 75% occur in the US.
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At what time of year are they most common?
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In the spring and early summer when cold, dry air from Canada collides with moist, warm air from the tropics.
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What is the length of an average tornado?
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The length of its path of destruction varies, but it is usually about 8 km long and 10-60 m wide.
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What is the wind speed of an average tornado?
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Between 120 and 180 km/h.
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What is a hurricane?
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It is a large, rotating tropical weather system with wind speeds of at least 119 km/h. These are the most powerful weather systems on Earth.
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What is another name for a hurricane?
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In the western Pacific they are called typhoons. In the Indian Ocean they are called cyclones.
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Where do hurricanes usually form?
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In the area between 5 degrees and 20 degrees north and south latitude over warm, tropical oceans.
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