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The layers of air that surround the earth

air pressure

The force of the weight of air pressing down on a unit of area

relative humidity

A comparison of the actual amount of water vapor in the air to the amount of water vapor that would be in the air if it were saturated


The boundary between two air masses that collide


The average of all weather conditions in an area over a period of time


A strong storm with rain, lightning, and thunder


A violently rotating column of air that extends downward from a thundercloud and touches the ground


A large, rotating tropical storm system with wind speeds of at least 74 miles per hour


A winter storm with strong winds and large amounts of heavy, blowing snow

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