Weather Fronts and Air Masses

Air Mass

A large body of air that has the same temperature and moisture level throughout. There are 4 types of air masses in the United States.

Air Mass

A huge body of air with similar temperature, humidity, and air pressure at any given height.

4 Characteristics of Air Masses

Tropical - Warm - formed in tropics

Polar - Cold - formed near N & S poles

Maritime - Wet - formed over oceans

Continental - Dry - formed over land

4 Major Types of Air Masses

mT - Maritime Tropical - warm & wet

mP - Maritime Polar - cold & wet

cT - Continental Tropical - warm & dry

cP - Continental Polar - cold & dry

Front

​The boundary where two air masses meet and weather occurs.

Cold Front

A cold front forms when cold air moves under warm air. Since the warm air is less dense the cold air pushes the warm air up. Cold fronts can and usually do produce thunderstorms. They are usually followed by colder and drier air.

Cold Front

cold air pushes underneath warm air quickly (showers and thunderstorms)

​Cold Front

• Cold air mass pushes warm air mass up

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• Cumulonimbus clouds form

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• Heavy rain, thunderstorms, and snow occur at a cold front​

Warm Front

A Warm Front forms when warm air moves over colder denser air and gradually replaces the colder air. Warm Fronts generally bring rain and are followed by clear and warm weather.

Warm Front

Forms when warm air moves toward cool air (steady precipitation)

​Warm Front

• Warm air mass stretches over coldair mass

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• Stratus clouds are formed

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• Steady light rain or snow occur at a warm front​

Stationary Front

A Stationary Front occurs when a cold air mass and a warm air mass meets but neither have the force to push the warm air mass up over the cold air mass. The two air masses remain separate creating a Stationary Front. A Stationary Front usually creates several days of rainy weather.

​Stationary Front

• Forms when a cold front or warm front stops moving

• The 2 air masses are pushing against each other, but neither is powerful enough to move the other

• Creates seveal days of rainy weather

Occluded Front

^{An Occluded Front forms when a warm air mass is caught between two colder air masses. The cold air mass moves under the warm air mass and pushes it up. The coldest air mass moves forward until it meets a cold air mass that is warmer and less dense. The coldest of these two air masses moves under and pushes up the warm air mass. Sometimes the two cold air masses meet together and mix. This Front bring lots of rain and snow.}

​Occluded Front

• A warm air mass is caught between 2 colder air masses

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• Brings LOTS of rain and snow​

Multiple Choice

If it is drizzling rain outside, what type of front has occured?

• Warm Front

• Cold Front

• Maritime

• Polar

Multiple Choice

Uh Oh! Severe Thunderstorm is happening. What type of front has occurred?

• Cold Front

• Warm Front

• Tropical

• Continental

Multiple Choice

It has been raining for days and Mrs. Latham wants to wash her car. What kind of front do you think could have caused all this rain.

• Warm Front

• Cold Front

• Occluded Front

• Stationary Front

Multiple Choice

It has been raining on and off today. The rain has finally stopped and Mrs. Latham takes her dog Shiloh for a walk but it is very warm outside so they don't walk long. What kind of Front do you think caused today's weather?

• Cold Front

• Warm Front

• Occluded Front

• Stationary Front

Multiple Choice

It has been thundering and lightning today and Mrs. Latham's dog has been so scared. When it finally calms down she takes her dog Shiloh out to use the bathroom. Burr she should have put a jacket on it is very cool outside but at least it is not raining anymore. What kind of Front do you think caused the weather today?

• Cold Front

• Warm Front

• Occluded Front

• Stationary Front

Multiple Choice

Mrs. Latham went to bed last night and it was cold but not really cold. When she woke up this morning it is much colder and it had snowed over 5 inches over night. What kind of Front do you think caused the weather last night?

• Cold Front

• Warm Front

• Occluded Front

• Stationary Front

Multiple Choice

Mrs. Latham went to bed last night and it was cold but not really cold. When she woke up this morning it is much colder and it had snowed over 5 inches over night. What kind of Front do you think caused the weather last night?

• Cold Front

• Warm Front

• Occluded Front

• Stationary Front

Multiple Choice

Look at this front coming in and tell me what weather is coming towards TN.

• warm and sunny

• cold and sunny

• warm with rain

• cold with rain

Multiple Choice

Look at the incoming front and tell me what type of weather PA is currently having.

• warm and sunny

• cold and sunny

• warm with rain

• cold with rain

Multiple Choice

Which front causes thunderstorms?

• Warm Front

• Cold Front

• Stationary Front

Multiple Choice

Which front causes drizzly rain?

• Warm Front

• Cold Front

• Stationary Front

Multiple Choice

Which front causes extended periods of rain?

• Warm Front

• Cold Front

• Stationary Front