air masses and fronts 2013

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?