An air mass is a large body of air with similar temperature, pressure, and humidity levels throughout. There are four main types of air masses: maritime, continental, polar, and tropical. Air masses get their properties from spending prolonged periods over certain areas, such as oceans or polar regions. When two different air masses meet, fronts are formed. The three main types of fronts are cold fronts, warm fronts, and stationary fronts.

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?