Understanding Air Masses & Fronts in Weather Systems

1. Air Masses & Fronts

2. Weather is caused by the movement & interaction of air masses

3. Air Mass- large body of air that has properties similar to the part of the Earth’s surface over which it develops • Each Mass is described with a Temperature & Moisture • Ex: Hot / Dry • Ex: Cold / Moist

4. Characteristics of Air • Air mass that forms over tropics is _______ than one that forms over the northern regions. • Air mass that forms over water is more ______ than one that forms over dry land.

5. Highs & Lows • Recall: Winds blow from an area of ______ pressure to an area of _____ pressure! • (high to low)

6. HIGH PRESSURE SYSTEM • Associated with fair / nice weather because the high pressure does not allow air to rise and form clouds • Hint: Think of High 5= Good Weather • Or Thumbs UP!

7. LOW PRESSURE SYSTEM • Associated with cloudy weather because the warm air rises and forms clouds • Thumbs Down

8. Fronts- boundary that forms between 2 different air masses • It is usually cloudy and stormy at a front • 4 Types • Cold • Warm • Occluded • Stationary

9. Familiar Fronts In your journals, identify these symbols

10. Front Drawings • Divide your paper into four equal sections • Read the FRONTS section on page 127 & 128 • Label each section with the 4 fronts: • Cold Front, Warm Front, Occluded Front, Stationary Front • Describe what happens at each front & what type of weather occurs • Draw a picture of each front & use Red & Blue colored pencils to add color. • INCLUDE THE SYMBOL OF THE FRONT!!!!!!

11. Cold Front

12. Cold Fronts Continued • Fronts move in the direction they are headed! • Tips: The blue triangles on a cold front= think of icicle • Q: What types of temperatures are left after a cold front moves through? • Q: What direction is this cold front moving?

13. Warm Front

14. Warm Fronts Continued… Hint: The half circles on a warm front= think of the sun • Q: What types of temperature are left after a warm front moves through? • Q: What direction is this warm front moving?

15. Stationary Front • Neither cold nor warm air advances. • Hint: Think of the line of scrimmage in a football game when both teams equally push against each other • OR a Stationary Bike!

16. Occluded Front

17. Occluded Front Continued… • Hint: The 2 C’s in oCCluded for 2 cold air masses. • Cold air masses close out the warm air from the surface. • The only front that includes ____ air masses. ( How many air masses are involved?)