WEATHER PATTERNS

1
WEATHER PATTERNS

• Chapter 15.2
• Pages 432 - 439

2
Air Masses

• A large body of air with similar properties such
  as temperature and humidity.
• They are similar to the surface over which they
  develop.
• Warm temperature (tropical areas)
• Cold temperature (polar areas)
• High humidity (maritime)
• Low humidity (continental)

3
Pressure Systems

• High pressure are areas where air is moving
  towards the earth.
• Low pressure are areas where air is moving away
  from the earth.
• High pressure usually means good weather.
• Low pressure usually means cloudy weather.

4
Weather Fronts

• The boundaries between two different air masses
• Storms and precipitation occur at fronts
• Four different types of fronts

5
Warm Front

• Warm air slides over cold air.
• Precipitation occurs over a wide area.

6
Cold Front

• Cold air pushes under warm air
• Narrow band of violent storms

7
Occluded Front

• 2 cold air masses merge and force the warm air
  between them to rise.
• Strong winds and heavy precipitation may occur.

8
Stationary Front

• Air pressure causes either a warm or cold front
  to stop moving.
• Light winds and precipitation across the entire
  frontal region are common.