Air Masses and Fronts

Air masses take on the characteristics of the area where they form.

Air masses are classified according to their temperature and moisture content

Warm air forms over tropical regions near the equator.

T- Tropical

Cold air forms over polar regions.

P- Polar

Wet air masses form over water

m- maritime

Dry air masses from over land.

c- continental

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Moisture content is noted by the first letter.

m – maritime – wet

c – continental – dry

Temperature is noted by the second letter.

P – polar – cool

T – tropical - warm

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What are the four types of air masses?

Maritime Tropical (mT)

Maritime Polar (mP)

Continental Tropical (cT)

Continental Polar (cP)

How do air masses move?

The prevailing westerlies are

the major wind belts in the

United States, between 30

and 60 degrees North

Prevailing westerlies push air

masses from west to east.

Fronts A front is a boundary

between two air masses of different density, moisture, and temperature, the collision often causes storms and weather changes.

A front may be 15 to 200 kilometers wide and extend as much as 10 kilometers up to the troposphere.

The kind of front that develops depends on the characteristics of the air masses and how they move.

There are four types of fronts.

Cold Fronts.

Warm Fronts.

Stationary Fronts.

Occluded Fronts.

Cold Fronts

Cold air mass meets a warm air mass and pushes the warm air mass out of its way.

Bring thunderstorms, rain or snow.

Most tornadoes develop from thunderstorms on the edge of a cold front.

Cold fronts are followed by cooler drier air.

Warm Fronts

Warm air mass meets a

cold air mass and

pushes the cold air

mass out of the way.

Brings drizzly

precipitation.

Followed by clear warm

weather.

Stationary Fronts

Cold air meets warm air.

Not enough force to move

either front.

Many days of cloudy, wet

weather.

Occluded Fronts

Warm air caught between

two cold air masses.

Brings cool temperatures

with large amounts of rain

or snow.

Cold Front, Warm Front, Stationary

Front and Occluded Front Animation

http://www.stevemcentee.com/animation3.html

Click on the link above.

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1. Describe a maritime polar (mP) air mass, in terms of moisture and temperature.

2. What is the name of an air mass that forms over water?

3. What is the name of an air mass that forms over land?

4. What is the name of an air mass that forms in a cold region?

5. What is the name of an air mass that forms in a warm region?

6. Describe a continental tropical (cT) air mass, Moisture and temperature.

7. The boundary between two air masses is called a ______________________.

8. A cold air mass meets and pushes a warm air mass out of the way.

What type of front am I?

9. A warm air mass is trapped between to cold air masses.

What type of front am I?

10. A warm air mass meets and pushes a cold air mass out of the way.

What type of front am I?

11. I am a front that brings drizzly rain and am followed by warm clear weather. Name me

12. A cold air mass meets a warm air but neither is very strong. They are separated and many days of wet , cloudy weather occur.

Section Review Questions

Answer the following questions on the paper provided.

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