1. Mrs. Wharton’s Science Class
Air Masses and Fronts
Mrs. Wharton’s Science Class

2. What is an Air Mass?
-A large body of air that takes on the characteristics of the area over which it forms
-properties of temperature and moisture content are similar in any horizontal direction
-Usually cover hundreds of thousands of square miles

3. Naming Air Masses
Air masses are named by combining their temperature and moisture characteristics:
Moisture:
Dry: Continental (c)
Moist/Humid: Maritime (m)
Temperature:
Warm/Hot: Tropical (T)
Cool/Cold: Polar (P)
Extremely Cold: Arctic (A)

4. Types of Air Masses warm, humid air mass: maritime tropical (mT)
warm, dry air mass: continental tropical (cT)
cool, humid air mass: maritime polar (mP)
cold, dry air mass: continental polar (cP)
Extremely cold, dry air mass: arctic (A)

5. Where are the air masses in the US?

6. Air masses of North America
Maritime
Polar
Continental Polar
Maritime
Polar
Continental Polar
Continental
Tropical
Maritime
Tropical
Maritime
Tropical
Air masses of North America

7. What happens when 2 air masses meet?

8. What is a Front?
The narrow region separating 2 air masses of different densities
The type of front which develops depends on the types of air masses involved.

9. 4 Types of Fronts
Cold
Warm
Stationary
Occluded

10. Cold Fronts
Cool dense air displaces warm air and forces the warm air up along a steep front.
Usually produces clouds, showers, and sometimes thunderstorms

11. Cold fronts are like snow plows
Clouds form mT cP

12. Warm Fronts
Advancing warm air displaces cold air that produces a gradual frontal slope rather than a steep boundary
Characterized by extensive cloudiness and precipitation

13. Stationary Fronts
Occur when a cold and warm air mass are in contact but neither are advancing at that boundary.
Cold Air
Warm Air

14. Occluded Fronts
When cold air mass moves so rapidly it overtakes a warm front and wedges the warm air upward
Precipitation common on both sides of the front

15. Lets Review…
What are the types of air masses? (think about temperature and moisture content)
What are the 4 types of fronts?
How does each of the fronts look on a weather map?