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Thunderstorms. Chapter 3 Section 2 Pages 83-85. Stormy Weather. A Storm is a violent disturbance in the atmosphere Involve sudden changes in air pressure Causes rapid movement of air. Thunderstorms. Heavy rain storms ( and sometimes hail ), accompanied by thunder and lightning
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Thunderstorms Chapter 3 Section 2 Pages 83-85
Stormy Weather • A Stormis a violent disturbance in the atmosphere • Involve sudden changes in air pressure • Causes rapid movement of air.
Thunderstorms Heavy rain storms (and sometimes hail), accompanied by thunder and lightning Form within large cumulonimbus cloudsor thunderheads.
How Thunderstorms Form • Warm, humid air is forced upward at a cold front • Air rises rapidly • Cools and forms a dense cumulonimbus cloud.
Lightning • Positive and negative charges build up in the storm clouds from friction of ice crystals • Lightning is the sudden discharge of this built up energy • May occur cloud to cloudORcloudtoground.
Thunder • Lightning super-heats the air around it to 30,000°C (hotter than the sun’s surface!) • The rapidly heated air expands suddenly and explosively • Thunder is the sound of the explosion • Thunder is heard after lightning because light (299,792,458 m/s) travels faster than sound (340.29 m/s).
Thunderstorm Safety • If outside: • Avoid touching metal objects because they conduct electricity • Lightning usually strikes the tallest objects • Trees, house or flag poles.
Thunderstorm Safety • If outside in an open area: • Find an area low away from trees, fences and poles • Crouch down with your head down and hands on your knees • If swimming or on a boat, seek shelter away from the water.
Thunderstorm Safety • If inside: • Avoid touching phones, electrical appliances, or plumbing. They conduct electricity • Cars are safe because they carry electricity around the metal shell, but do not touch metal in the car.
Exit Pass How does electric charge build up in clouds? What causes the sound of thunder?