STORMY SKIES Thunderstorms are a common weather disturbance They are usually violent and short-lived They almost always include thick clouds heavy rain or hail and strong winds They also include lightning and thunder In ancient times people believed that angry gods threw lightning bolts from the heavens It was not until the 1700s that scientists offered an explanation for lightning Lightning is electricity released released from Earth’s atmosphere atmosphere during thunderstorms 4 Thunderstorms occur in almost every region of the world They usually include include thick clouds rain or hail lightning lightning thunder and strong winds
VOCABULARY Electricity is the flow of tiny particles called electrons and protons It can also mean the energy you get when electrons flow from place to place Lightning is most common in tropical regions However thunderstorms with lightning happen in almost almost every region of the world An estimated 1,800 thunderstorms occur around the world at any given time These storms produce eight million flashes of lightning each day If the electricity in one lightning bolt could be harnessed it could power nearly sixty homes for one day 5
Thunderstorms Thunderstorms happen happen when hot moist air rises quickly to cooler cooler parts of the atmosphere There the air cools and clouds and rain form Lightning Lightning develops inside the clouds As the lightning heats the air in its path the air expands very quickly The air then shrinks after the lightning is passed This sudden air movement causes the sound of thunder Meanwhile cooled air sinks toward the ground This movement of air causes heavy winds The stages of a thunderstorm include rising hot moist air the formation of clouds and rain and the occurrence occurrence of lightning and thunder When the air cools the clouds sink and later disappear 6
THINK ABOUT IT Sunlight heating air causes winds and moisture to move which can cause storms On a small scale water can be heated to boiling in a pot What can you learn by looking at water boiling in a pot that can help you understand thunderstorms Some thunderstorms are severe enough to produce produce tornadoes A tornado is a column of strongly rotating winds It can produce winds as fast as 300 miles 483 kilometers kilometers per hour Winds swirling around a moving storm can turn fast enough to form a tornado 7
