Conditions for Cloud Formation
 Clouds are made of which 2 states of Matter?
– Liquid
– Ice
CONDENSATION NUCLEI:
Surface for water vapor to condense on (dust,
smoke, salt)
-How does this help the formation of clouds?
Other ingredients for Cloud Formation
1. Air must be saturated
2. Cooling leads to condensation
3. LOW PRESSURE
Causes air to e x p a n d…cooling air to its
dewpoint
Cloud Video
Convective Cooling
 The lowering of the temperature of a mass of air
due to its rising and expanding.
FORCEFUL LIFTING
FORCEFUL LIFTING
1. Frontal Wedging
- a moving mass of warm air encounters a
mass of cold air in its path and rises up
over it
2. Orographic Lifting
- An air mass is force from a low elevation to a
higher elevation as it moves over rising
terrain.
Forceful Lifting: Frontal Wedging
Forceful Lifting: Frontal Wedging
Forceful Lifting: Frontal Wedging
Forceful Lifting: Frontal Wedging
Orographic Lifting
RAINSHADOW Effect
Forceful Lifting
FOG
 The result of
condensation of
water vapor in the
air. Formed near
the surface of the
earth.
 Like a cloud, only
lower.
FOG
 Radiation fog
– At night, layer of air
above ground is
cooled to it’s dew
point
 Advection fog
– Warm moist air
moves over a cold
surface (mostly
coastal)
Precipitation
 Work on 5.04 table
– Use pg. 489-493
– Due Monday!
CLOUD CLASSIFICATION
CLOUD TYPES
 There are three major
cloud types:
– Stratus- low layers of
clouds. These clouds
can bring light rain.
Fog is usually a layer of
stratus clouds touching
the ground.
CLOUD TYPES
 Cumulus- mid-level
clouds that are fluffy and
have flat bases. Large
cumulus clouds can
produce thunderstorms.
 Cirrus- high-level clouds
that are wispy. No
precipitation is associated
with these clouds.
CLOUD TYPES
 Cloud prefixes & suffixes:
–
–
–
–
–
Cirro- high level clouds
Alto- mid-level clouds
Strato- low-level clouds
Nimbo/nimbus- rain clouds
Cumulo- towering clouds
 These terms can be
combined to form several
cloud names.
CLOUD TYPES
 Cumulonimbus- towering
cumulus cloud capable of
thunderstorms.
 Stratocumulus- low-level,
layered and puffy clouds.
 Nimbostratus- low layers
of clouds that are capable
of bringing long, steady
rain.
CLOUD TYPES
 Cirrostratus- high, thin
layered clouds. These can
form halos around the
moon or sun.
 Altostratus- mid-level,
layered clouds. These
look gray/blue. The sun is
visible through them.
 Altocumulus- mid-level
clouds that are puffy.
 Cirrocumulus- high-level
clouds that are puffy.