Download Warm Fronts

Fronts
Fronts
• Air masses move according to global
winds and currents.
• The area between two air masses is
known as a front.
• Meteorologists have determined four main
types of fronts: Cold, warm, stationary
and occluded.
5 Characteristics of
a Front
• Sharp temperature changes over
a relatively short distance.
• Changes in air moisture content
• Shifts in wind direction
• Pressure changes
• Clouds and precipitation
Cold Fronts
• Cold air mass reaches a warm air mass.
• Because the cold air is more dense then
the warm air, it pushes the warm air
upwards.
• Cumulus clouds or cumulonimbus clouds
are often seen.
• Cold fronts often bring rain, strong storms
or tornadoes.
Cold Fronts
In the summer, cold
fronts can trigger:
• thunderstorms
• large hail
• dangerous winds
• tornadoes
Warm Fronts
• A warm air mass reaches a cold air mass.
• Warm air rises slowly over the cold air
mass.
• Usually forms stratus and/or nimbostratus
cloulds that carry light rain or snow.
• Once the air mass has passed, the
temperature tends to be warmer then
before.
Warm Fronts
Warm Fronts
• Temperature – rises slowly
• Pressure – slight rise, then fall
• Clouds – strato- and cirro• Precipitation – long, steady
• Winds – variable and light
• Typically will have affect for days
Stationary Fronts
• A cold mass of air and a warm mass of air
are in contact with no movement.
• Warm air rises and condenses to form
stratus clouds and usually rain.
• The front can be stationnary for many
days.
Occluded Fronts
• A cold front reaches a warm front and
moves very slowly. The two air masses
are blocked.
• Many types of clouds are seen.
• Occluded fronts generally bring a long
period of hard precipitation.
Occluded Fronts
Fronts and their
symbols
• Notes
– Answers
• Video – Weather fronts