Download Air Masses and Fronts

Air Masses and Fronts
Main Idea: Weather changes often occur at fronts, where different air
masses meet.
How Do Air Masses Affect Weather?
Air massA large region of atmosphere where the air has similar properties.
Air masses
» Named from the region they come from.
» Get properties from region they come from.
» Are moved by global winds.
 In U.S they move west to east.
FrontsA boundary between air masses with different temperatures.
»
Fronts
» The “meeting place” of different air masses.
» Weather changes rapidly.
» Often cause rainy, unsettled weather.
How Do Fronts Affect Weather?
1. Cold Front

Cold air masses move under warm air masses.

Bring brief heavy storms.

After storm there are clear skies. Weather is cooler and drier.
2. Warm Front
Warm air moves over cold air.

Bring light, steady rain or snow that can last for days.

After weather is warmer and more humid.