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An air mass A large region of air with similar

temperature and humidity

throughout.

Air masses are defined by their place of origin

An air mass Humidity

m = maritime (forms over ocean) making

the air humid

c = continental (forming over land)

making air dry

Air masses TEMPERATURE

P = polar (northern) making the air cold

T = tropical (close to equator) making the

air warm

What kind of air mass?

http://www.physicalgeography.net/fundamentals/7r.html

mT = warm and moist

mP = cold and moist

cT = warm and dry

cP= cold and dry

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Fronts  A front is a dividing line between

two distinct air masses

Front symbols   1. Cold front   2. Warm front   3. Stationary front   4. Occluded front   5 - 8 not fronts

Cold Front

–  Causes a quick rising of warm air along the leading edge of the front.

–  Causes formation of cumulonimbus clouds and precipitation ahead or during the passing of the cold front.

–  Temperatures and dew points fall as a cold front passes

–  Have a steeper slope than warm fronts and move quickly.

~ Occurs when cold air moves into warm air ~ 45°

55°

Cold Front ~ Occurs when cold air moves into warm air ~

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Warm fronts ~ Occurs when warm air moves into cold air ~

Warm fronts   Gentle, slower, rising of

warm air occurs with a warm front.

  Clouds related to a warm front are layered stratus clouds: cirrostratus, altostratus,

  Cirrus clouds on the leading edge

  Temperatures and dew points rise as a warm front passes

  Move more slowly

68°

47°

Stationary fronts

  Two fronts, a warm and cold, push against each other and have stopped moving.

  Can result in extended periods of precipitation

source: USA TODAY research by Chad Palmer, Graphic by John Herne

Occluded Fronts   From when a warm air

mass is centered above two merging cold air masses.

  These develop as the faster moving cold air mass catches up to the warm air mass and pushes it up and over the center of the Low pressure cell.