2. Precipitation
• The amount of precipitation a location receives
depends on its distance from the sea and the
prevailing winds
• Precipitation = drizzle, showers, heavy rain, hail, or
snow — all have an impact on the location they fall
• Western Canada experience three types:
orographic, convectional, and frontal
4. Orographic Precipitation
• The prevailing winds blow moist air onshore
• As the air hits higher land, the air is forced to rise
• When air rises it begins to cool
• When it can no longer hold all its water; it starts to
condense and form clouds
• Orographic = affected by mountains
6. Convectional Precipitation
• Water in the ocean and lakes is warmed by the sun
• The air above becomes heated
• This makes the air less dense, so it rises; as it rises it
cools
• Cool air can not hold as much water vapour =
condensation occurs, gradually becoming clouds
8. Frontal Precipitation
• Two air masses of warm and cold air meet, causing
a front
• When they meet, the less dense, warm air is forced
above the denser, heavier cold air
• When air can no longer hold its water, clouds form
