2. Air Mass
The air over a very large region with similar + constant properties near the surface.
Ex: wind, temperature and moisture content .
Cold + moist
Cold + dry
Hot + moist (humid)
Hot + dry

3. Types of Air Masses
*Named according to where they originate.

4. Polar (P) air mass: COLD Tropical (T) air mass: HOT Continental (C) air mass: DRY Maritime (M) air mass: MOIST

5. When 2 different air masses meet, FRONTS are formed
1. Cold Front
2. Warm Front
3. Stationary Front
4. Occluded Front

6. Cold Front Cold air replaces warm air.
When a cold front moves through, temps can drop drastically!

8. Warm Front Warm air replaces cold air.
When a warm front passes through, the air becomes warm + humid.

9. When a warm or cold front stops moving, it becomes a stationary front.

10. Occluded Front When a fast moving cold front overtakes a warm front.
Lifts the warm air off the ground completely.

11. Front Symbols