Air Masses
EQ: How do meteorologists use air masses and weather fronts to predict our weather?
http://www.weatherquestions.com/What_is_an_air_mass.htm
• http://www.weatherquestions.com/What_is_an_air_mass.htm
An air mass is a large body of air with similar temperature, pressure, and humidity levels throughout.
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.
Air Masses
• Four types of air masses– Maritime– Continental– Polar– Tropical
Air Masses
Continental Maritime• Form over land and are dry • Form over water and are
moist
Air Masses
Tropical• Form over the tropics (low
latitudes)• Warm/Hot
Polar• Form at the polar regions of
Earth (high latitudes)• Cool/Cold
Air masses
Why does our weather change?
Air masses move!
How?
Global winds push air masses around the Earth!
Air MassesReflect
• 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.
Fronts• A front is a place where two different air masses
meet • Three main types• A “battle” between air masses
Continental Polar
Maritime Tropical
FRONT
Cold Fronts
• Click for Animation
Cold Front
• Moves quickly and can produce thunderstorms
• After it moves through, skies will be clear and temperatures will be cooler
Cold FrontReflect
• 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.
Warm Front
• Click for Animation
Warm Front
• Moves slower than cold fronts• Brings humid weather and sometimes rains
for days
• After it moves through, temperatures are warmer
Warm FrontReflect
• 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?
Stationary Front
• Click for Animation
Stationary Fronts
• Two air masses next to each other, but neither moves.
• Weather remains the same for days
Stationary FrontReflect
• 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?