Air Masses and Fronts

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Air Masses and Fronts
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What changes do you feel in the weather right
before a thunderstorm?

• Skies get dark
• Gets windy
• Gets colder

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Recipe for a storm

• Compare the skies between a thunderstorm and a
  tornado.
• Do you see any similarities?
• Do you see any differences?

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Thunderstorms
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Tornadoes
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Can air move around?
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Air Mass animation

• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es2001/es2001page01.cfm?cha
  pter_novisualization
• All around the earth, large masses of air move
  around and constantly change the weather.
• They are named based on where they are coming
  FROM.

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What type of weather would the following air
masses bring?
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What do the following terms mean?

• Continental
• Land
• Maritime
• Water
• Polar
• cold
• Tropical
• warm

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Copy the following slides on page 14 of your
Interactive Notebook

• If it is in YELLOW, you are to copy it in your
  notebook.
• Title the page Air Masses Descriptions

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There are four types of air masses.

• Air masses are named based on where they are
  coming FROM

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Continental Polar

• Cold, dry air mass that forms over central and
  northern Canada and Alaska

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Continental Tropical

• Hot, dry air masses that form over Southwest and
  northern Mexico

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Maritime Polar

• Cool, humid air masses that form over the icy
  cold North Pacific and North Atlantic oceans.

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Maritime Tropical

• Warm, humid air masses that form over tropical
  oceans such as the Gulf of Mexico

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Classifying Air Masses
Wet (Maritime) Dry (Continental)
Warm (Tropical) Maritime Tropical Continental Tropical
Cold (Polar) Maritime Polar Continental Polar
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Write on page 13Fronts Activity

• Listen to the instructions
• Do activity

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On page 13 of your Interactive Notebook, answer
the questions below.

• The water represents air. Knowing this, explain
  how you think air behaves when air of different
  temperature meet.
• Write your answer in complete sentences.
• Using the color pencils, draw what you made and
  label.

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Fronts (Copy on page 13)

• A boundary created when two air masses meet.
• Fronts are named for the air mass that is moving.

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In the activity that we just did

• Where is the front?

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(No Transcript)
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Fronts animation

• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es2002/es2002page01.cfm?cha
  pter_novisualization

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Fill in the Weather Fronts chart as you follow
along the next few slides.
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Cold Front

• Cold dense air moves in and pushes warm air out
  of the way
• Cold fronts move very quickly and bring short
  periods of rain/thunderstorms
• Lower temperatures are behind the front
• SYMBOL the direction of the arrows points
  towards the direction the front is MOVING

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(No Transcript)
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A cold front
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Warm Front

• Warm air moves up the cold front as it slowly
  displaces and overtakes the cold air
• Warm fronts move slowly, and bring many days of
  steady precipitation
• Higher temperatures are behind the front
• SYMBOL direction of half-moons is the
  direction the front is moving

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(No Transcript)
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Warm front
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Animations

• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es2002/es2002page01.cfm?cha
  pter_novisualization
• Cold front
• Links to cold front videos

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Stationary front

• Created when cold and warm masses meet but
  neither one has enough force to move the other
  out of the way.
• The water vapor in the warm air condenses into
  rain, fog, snow, clouds.
• Can bring many days of precipitation

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(No Transcript)
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Links

• Stationary front videos

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Occluded front

• Is created when a warm air mass is caught between
  two cooler air masses.
• The two denser cooler air masses cut off the warm
  air mass from the ground.
• As the warm air mass cools, it may turn cloudy,
  rainy or snowy.

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(No Transcript)
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Watch video clip of a weather report.

• http//www.youtube.com/watch?vHQrB37YQo9Y
  start at 210
• http//www.youtube.com/watch?vOdcCMn5sbzMfeature
  related start at 130
• http//www.youtube.com/watch?vnS1nwfRUaaUfeature
  related start at 30

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Do a weather report
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(No Transcript)
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Use the graphic organizers and your interactive
notebook to complete your homework.