1. Air Masses and Fronts

2. Air Mass Large body of air passes slowly over a large area.
Takes on the properties of that air mass.
Usually temperature and humidity.
Source region is where the air mass comes from.
U.S. is not a good source region because weather disturbance move quickly which limits air to stay in one area.

3. 3 Major Air Masses
3 Air Masses
Polar
Artic
Tropical

4. 3 Locations Maritime – ocean Continental – land
Artic – Very cold land up near Canada.

5. Fronts Where 2 air masses meet with different properties.
Area between the 2 air masses is called the frontal zone.
Temperature, humidity, and wind direction can vary greatly.
Strong storms, tornadoes and squalls can occur.

6. Types of fronts
Cold Front: edge of cold-air mass: the boundary zone of an advancing cold-air mass as it replaces warmer air
Warm Front: A front along which an advancing mass of warm air rises over a mass of cold air

7. More Fronts
Occluded Front: a composite front formed when a cold front overtakes a warm front and forces it aloft
Stationary Front: a weather condition in which the boundary between a cold air mass and a warm air mass is stationary