3. When a large body of air moves
it causes weather changes.
Air mass
Large body of air.
4. Air masses
can be:
Hot air mass Cold air mass
All of an air mass has the same
temperature and same amount of
moisture level (amount of water in
the air).
5. Blue arrows are cold air masses
Red arrows are hot air masses
6. Temperature and moisture level depend on
where the air masses where formed.
Dry air
mass
Formed
over land
Wet air mass
Formed over
oceans or
seas
Hot air
mass
Come from
the south
Cold air
mass
Come from
the north
7.
8. Type of weather caused by different air
masses:
Cold, dry
air masses
Cool
weather, with
little or no
precipitation
Warm, moist
air masses
Lot of
precipitation
Warm, dry
air masses
Warm
weather +
little or no
precipitation
Cold, Wet
air masses
Snow
13. 1) Cold Front
Cold air moves under warm air.
Warm air mass moves up and cools down.
Water vapor condenses and moves up.
It might rain or thunderstorms develop along
the front
As the cold air mass moves forward the
weather becomes cooler.
14.
15. 2) Warm Front
Warm air moves slides over cold air.
Warm fronts moves slowly.
Steady rain instead of thunderstorms.
Warm fronts are followed by clear, warm
weather.
16.
17.
18. 3) Stationary front
A front that stays in one place for many days
Happens when two air masses do not have
enough energy to move.
Steady rain instead of thunderstorms.
Weather along the stationary front is often
cloudy and wet
This kind of front can leave inches of snow or
cause flooding.
29. Many weather maps show temperatures.
The temperature can be:
Written on a map. Shown using colors.
Red (Very hot)
Orange (Warm)
Green (Cool)
Yellow (mild)
Blue (Very cold)
