AIR MASSES AND
FRONTS
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Air masses take on the characteristics of the area where they form.
Air mass temperature and moisture are consistent throughout.
•
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 form 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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4
5
6
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• mP- maritime polar air mass
• cP – continental polar air mass
• mT – maritime tropical air mass
• cT – continental polar air mass
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•
A front is a boundary between air
masses.
•
Four types of fronts and map symbols
1.
2.
3.
4.
Cold front
Warm front
Occluded front
Stationary front
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COLD FRONT
• 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 front followed by cooler drier air.
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COLD FRONT
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WARM FRONT
• 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.
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WARM FRONT
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STATIONARY FRONT
• Cold air meets warm air.
• Not enough force to move either front.
• Many days of cloudy, wet weather.
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STATIONARY FRONT
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OCCLUDED FRONT
• Warm air caught between two cold air
masses.
• Brings cool temperatures with large
amounts of rain or snow
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OCCLUDED FRONT
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Cold Front, Warm Front and
Occluded Front Animation
• http://www.classzone.com/books/earth_scien
ce/terc/content/visualizations/es2002/es2002
page01.cfm?chapter_no=visualization
• Click on the above links.
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Low Pressure L
• Air pressure pushing
down.
• “Low Blow”
• Winds, stormy
weather on its way!
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High Pressure H
• No air pressure
pushing down
• “High Sky-Clear
Sky”
• Clear sunny skies,
few or no clouds
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Low & High Pressure
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Quiz: Take this on the paper provided.
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.
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