Air Masses and Fronts Air Masses Air masses

Air Masses and Fronts

Air Masses • Air masses have the same properties as the surface over which it develops: Maritime = Wet m. P = wet/cold Continental = Dry c. P = dry/cold Polar = Cold m. T = wet/warm Tropical = Warm c. T = dry/warm

Air Masses in North America

Fronts • • A front is the boundary where two air masses meet. WARM AIR Types of fronts: 1. 2. 3. 4. Warm Front Cold Front Occluded Front Stationary Front FRONT COLD AIR

Warm Front • Warm air slides over departing cold air. • Brings drizzle followed by clear and warmer weather

Cold Front • Cold air pushes under a warm air mass. • Warm air rises quickly. • Brings heavy rain followed by cooler weather.

Occluded Front • Two cold air masses merge and force warm air between them to rise quickly. • Brings cooler temperatures and large amounts of rain and snow.

Stationary Front • Warm and cold air meet but remain separated. • Brings many days of cloudy wet weather.

Cyclones and Anticyclones • Areas of HIGH and LOW pressure • Cyclone = LOW PRESSURE = spin counterclockwise = associated with storms and precipitation • Anticyclone = HIGH PRESSURE = spin clockwise = associated with fair weather.

Cyclones and Anticyclones in the USA Rising air in CYCLONE (Low pressure) forms clouds and rain. Falling air in an ANTICYCLONE (High pressure) forms dry clear weather.

Fronts - Video