Air Masses and Fronts

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Transcript Air Masses and Fronts

Air Masses and Fronts
Air Masses
An air mass is a
huge body of air
that forms over
water or land in
tropical (hot)or
polar (cold)
regions.
Air masses can
be hot, cold,
wet, and dry
depending on
where they form
at, and the areas
they pass over.
When 2 air masses meet, they do not mix. What happens is that they
form a border that is known as a front. Most of the weather that we think
of happens along fronts.
Weather Fronts
There are 4
1. Warm Front
different types 2. Cold Front
of fronts.
3. Stationary
Front
4. Occluded
Front
Cold Front
 When a cold air mass
collides and slides
under a warm air
mass, we have a cold
front. This brings
thunderstorms,
tornadoes,
hurricanes, and
cooler temperatures.
Warm Front
 When a warm air
mass collides and
rides over a cold air
mass, we have a
warm front. This
brings warmer
temperatures and
long periods of
precipitation.
Stationary Front
 When a cold and
warm air mass meet
up and neither one
moves to the
frontal boundary,
we have a stationary
front. This may
produce long
periods of
precipitation.
Occluded Front
 When a cold air mass
pushes into a warm
air mass that is
behind a cool air
mass. The warm air
mass is pushed up
above the cooler air
masses. This may
bring long periods of
precipitation.
Front Symbols
 The direction that
the front is facing, is
the direction that
the front is moving
towards.
When warm air rises or cold air
sinks combined with the
spinning of the Earth, this
causes high and low air
pressure systems.
High/Low Pressure
Systems
 High Pressure
systems usually
signals fair
weather with the
winds circulating
in a clockwise
direction.
 Low Pressure
systems usually
signals
rainy/stormy
weather with the
winds circulating
in a counterclockwise
direction.
Thunderstorms
 A storm with
thunder, lightening,
heavy rains, and
strong winds;
usually forms within
a cumulonimbus
cloud. Usually
forms along a cold
front.
Tornadoes
 A tornado is a rapidly
whirling, funnel-shaped
cloud that comes down
from a storm cloud. The
low pressure and strong
winds cause great
damage to people and
their property. Likely to
form when
thunderstorms are
present.
Hurricanes
 A low pressure
tropical storm that
forms over warm
ocean water. Winds
move in a circular
pattern around the
center, or eye, of the
storm. The lower the
air pressure at the
center, the faster the
winds blow.