Download Weather Patterns

Air Masses and Fronts
(1)
Air Masses
 Air masses are large
bodies of air that have
the same properties as
the area of the Earth’s
surface over which it
forms and moves.
 For example, deserts
produce hot dry air
masses.
Air Masses (continued)
Cool
Dry
Cool
Moist
Warm
Moist
Warm
Dry
Cool
Moist
Warm
Moist
(2)
Fronts
 The place where air
masses meet is called a
front.
 Weather is caused by
the way these air
masses interact.
Cold Fronts
(3)
 Incoming dense cold air pushes up warm air
 This forms a narrow band of violent storms
Warm Fronts
 Warm air slides over departing cool air.
 This forms feathery clouds.
Occluded Fronts
 Two cool air masses meet and pushes up warmer air.
 This causes strong winds and heavy precipitation.
Stationary Front
 A cool air mass and a warm air masses meet and stop
moving (neither one advances).
 This causes a few days of rainy and windy weather.