1. Air Masses

2. Changes in weather are caused by the movement of air masses.

3. An AIR MASS is a very large volume or block of air w/ similar temp. & humidity (moisture) throughout.

4. An air mass’s humidity & temp. depend on the area where it formed or its source region.

5. Therefore you name air masses to describe their temperature & humidity. Moisture descriptions Temp. descriptions Continental (dry)Polar Maritime (wetter)Tropical

6. The 4 major masses are: Type/NameWhere if FormsTemperatureHumidity Maritime Polar Maritime Tropical Continental Polar Continental Tropical

7. Air masses and source regions for North American

8. Air masses and source regions for the world

9. AIR FRONTS

10. When two different air masses meet & don’t mix they make fronts.

11. Fronts bringing changes in the weather & possibly precipitation.

12. There are four types of fronts Cold Warm Stationary Occluded

13. https://s-media-cache-ak0.pinimg.com/originals/80/6d/36/806d36c0404d3afec7f55b24615a8092.jpg

14. After the front the weather usually is clear and sunny