Understanding Weather Fronts and Pressure Systems
This resource explains the dynamics of weather fronts and pressure systems. Cold fronts occur when a dense cold air mass overtakes a warmer one, leading to potential thunderstorms and heavy rain. In contrast, warm fronts involve a warm air mass gently ascending over a cooler one, resulting in prolonged precipitation. Low pressure systems, characterized by rising air, commonly bring unstable weather, while high pressure systems, associated with descending air, provide clear skies and stable conditions. Explore the impact of these systems on weather patterns.
Understanding Weather Fronts and Pressure Systems
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Presentation Transcript
Frontal Systems Section 15.2
Fronts • Air masses move due to worldwidewindcurrents. • The zone between air masses is called a front
Cold Fronts • This zone is formed where a moving cold air mass overtakes a warmer air mass. • The cold air is more dense than the warm air. It moves below the warm air and pushes the warm air upward, making clouds – often making rain. • Fast moving fronts can cause intense thunderstorms which are often accompanied by hail and even tornadoes.
Warm Fronts • This zone is formed where a warm mass overtakes a cooler one. The warm air gently rides up over the trailing end of the cold air mass. • Clouds form, bringing light rain or snow. • Precipitation may last much longer than it does at a cold front but the temperature will be warmer than before the warm front arrived
Low Pressure Systems • Where air rising in a counterclockwise direction creates a cyclone and leaves less dense air below. • Low pressure systems usually bring unstable weather conditions such as precipitation and storms • They develop with a front (between air masses)
High Pressure Systems • Where air descends (putting pressure on the ground below) in a clockwise direction – called an anticyclone. • High pressure systems bring clear skies with little moisture. • They can last several days
