Download Types of Precipitation

Types of Precipitation
• Orographic
• Frontal/cyclonic
• Convectional
Orographic Precipitation
• Orographic precipitation results when
warm moist air moving across the
ocean is forced to rise by large
mountains
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Frontal/Cyclonic Precipitation
• Cyclonic or Frontal precipitation results
when the leading edge of a warm, moist
air mass (warm front) meets a cool and
dry air mass (cold front)
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Frontal/Cyclonic Precipitation
The
molecules in the cold air are more tightly
packed together (i.e., more dense), and thus, the
cold air is heavier than the warm air
The
warmer air mass is forced up over the cool air.
As it rises, the warm air cools, the water vapour in
the air condenses, and clouds and precipitation
result.
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Convectional Precipitation
• Convectional precipitation results from
the heating of the earth’s surface
• The warm ground heats the air over it
and as the air warms, the air molecules
begin to move further apart
Convectional Precipitation
• As the air rises, it cools. Water vapour
in the air condenses into clouds and
precipitation
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Orographic
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Frontal/Cyclonic
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Convectional
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What is the dew point?
• The dew point temperature is the
temperature at which the air must
become cooled in order to become
completely saturated with water vapour
• If the air is cooled to the dew point
temperature, it will become saturated
Dew Point
• The dew point temperature can never
be higher than the air temperature
because when the two are equal, the air
is holding as much water vapour as it
can possibly hold and the air is
saturated
Review
• What are the 4 types of clouds we
learned about?
• What are the 3 types of precipitation we
learned about?
• What are the names of the instruments
used to measure weather and what do
they measure?