2. Air Masses
http://www.weatherquestions.com/What_is_an_air_mass.htm
EQ: How do meteorologists use air
masses and weather fronts to
predict our weather?

3. An air mass is a
large body of air
with similar
temperature,
pressure, and
humidity levels
throughout.
• http://www.weatherquestions.com/What_is_an_air_mass.htm

4. Air Masses
• Get their properties from spending many
days, even weeks, over the same area.
– Example: If an air mass sits over an ocean for
awhile, it becomes humid.
– If an air mass sits over land, it becomes dry.

5. Air Masses
• Four types of air masses
– Maritime
– Continental
– Polar
– Tropical

6. Air Masses
Continental Maritime
• Form over land and are dry • Form over water and are
moist

7. Air Masses
Tropical Polar
• Form over the tropics (low • Form at the polar regions of
latitudes) Earth (high latitudes)
• Warm/Hot • Cool/Cold

9. Air masses
Why does our weather change?
Air masses move!
How?
Global winds push air masses around the Earth!

10. Air Masses
Reflect
• M- Describe the four types of air masses.
• I- If you could become an air mass, which
would you be and why?
• U- What type of air mass do you think is
affecting us today and why?
• S- Create a flag for an air mass and explain
why you chose that air mass.

11. Fronts
• A front is a place where two different air masses
meet
• Three main types
• A “battle” between air masses
Maritime Tropical
Continental Polar
FRONT

12. Cold Fronts
• Click for Animation

13. Cold Front
• Moves quickly and can produce
thunderstorms
• After it moves through, skies will be clear and
temperatures will be cooler

14. Cold Front
Reflect
• M- Explain the types of weather associated
with a cold front.
• I- Write a skit for a cold front with two
characters: cold air mass and warm air mass.
• U- A cold front passed through last night.
Predict what the weather is like now?
• S- Create a metaphor: A cold front is
like a _______________________. Explain.

15. Warm Front
• Click for Animation

16. Warm Front
• Moves slower than cold fronts
• Brings humid weather and sometimes rains
for days
• After it moves through, temperatures are
warmer

17. Warm Front
Reflect
• M- Restate the cause of a warm front.
• I- Which type of front do you feel is the best
and why?
• U- Compare and contrast warm fronts and
cold fronts.
• S- What would it be like to be a warm front?

18. Stationary Front
• Click for Animation

19. Stationary Fronts
• Two air masses next to each other, but neither
moves.
• Weather remains the same for days

20. Stationary Front
Reflect
• M- Summarize the three types of fronts.
• I- You are charged with studying the effects of
air masses and fronts. How would you do it?
• U-Which type of front do you think is the most
destructive and why?
• S- Imagine you live in a world with only two
types of air masses. How would that effect
fronts?