Storms and the Movement of Air Textbook pages
AIR MASSES ► Huge bodies of air that are formed over water or land in tropical or polar regions. ► Temperature and humidity within the air masses is important to the weather conditions that develop.
FRONTS ► As air masses move and collide they form fronts between them.
WARM FRONTS ► A warm air mass collides and moves over a slowly moving cold air mass. ► Can bring long periods of precipitation and warmer temperatures.
COLD FRONTS ► Cold air mass slides under warm air. ► May produce thunderstorms, tornadoes, and cooler temperatures.
STATIONARY FRONTS ► A cold air mass and a warm air mass do not move at a front ► Produces long periods of precipitation.
OCCLUDED FRONTS ► A warm air mass is caught between two cold air masses. ► Causes clouds, rain and snow.
HIGH/LOW PRESSURE SYSTEMS ► Caused by warm air rising or cold air sinking combined with the spinning of the Earth which makes the air spin forming these systems.
High Pressure ► High Pressure Systems: signal fair weather with winds circulating around the system clockwise.
Low Pressure ► Low Pressure Systems: signal rain and stormy weather with winds circulating counter-clockwise
STORMS ► Occur when pressure differences cause rapid air movement causing severe weather conditions.
THUNDERSTORMS ► Storm with lightning, thunder, heavy rains, and strong wind that form within large cumulonimbus clouds. ► Usually form along a cold front.
TORNADO ► Rapidly, whirling funnel- shaped clouds that reaches down from a storm cloud. ► Very low pressure and strong winds can cause great damage. ► Likely to form within the frontal regions where strong thunderstorms are also present.
HURRICANE ► Low pressure tropical storm that forms over warm ocean water. ► Winds form a spinning circular pattern around the center (eye). ► The lower the air pressure at the center, the faster the winds blow.