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.

Air Masses and Air Masses and FrontsFronts

Air masses take on the characteristics of the area where they form. Air masses take on the characteristics of the area where they form. Air masses are classified according to their temperature and moisture contentAir masses are classified according to their temperature and moisture content

Warm airWarm air forms over forms over tropicaltropical regions near the equator. regions near the equator. T- TropicalT- Tropical

ColdCold airair forms over forms over polar polar regions.regions. P- PolarP- Polar

WetWet airair masses form over masses form over waterwater m- maritimem- maritime

Dry airDry air masses from over masses from over land.land. c- continentalc- continental

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Moisture content is noted by the first letter.Moisture content is noted by the first letter.mm – – maritimemaritime – – wetwetc c –– continental continental – – drydry Temperature is noted by the second letter.Temperature is noted by the second letter.PP – – polarpolar – – coolcoolTT – – tropicaltropical - - warmwarm

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What are the four types of air What are the four types of air masses?masses?

Maritime Tropical Maritime Tropical (mT)(mT)

Maritime Polar (mP)Maritime Polar (mP) Continental Tropical Continental Tropical

(cT)(cT) Continental Polar (cP)Continental Polar (cP)

How do air masses move? The prevailing

westerlies are the major wind belts in the United States.

Prevailing westerlies push air masses from west to east.

FrontsFronts A A frontfront is a boundary is a boundary

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

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

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

There are four types of There are four types of fronts.fronts.

Cold Fronts.Cold Fronts. Warm Fronts.Warm Fronts. Stationary Fronts.Stationary Fronts. Occluded FrontsOccluded Fronts..

Cold FrontsCold Fronts Cold air mass meets a warm Cold air mass meets a warm

air mass and pushes the warm air mass and pushes the warm air mass out of its way.air mass out of its way.

Bring thunderstorms, rain or Bring thunderstorms, rain or snow.snow.

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

Cold fronts are followed by Cold fronts are followed by cooler drier air.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 FrontsStationary Fronts Cold air meets warm air.Cold air meets warm air.

Not enough force to move Not enough force to move either front.either front.

Many days of cloudy, wet Many days of cloudy, wet weather.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.htmlClick 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 me12. 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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