Download Ch18.3 Cloud Notes

Ch 18.3 Clouds
• Objective: Be able to…
– Identify different types of clouds based on
their height and form.
– Define how clouds form
What are Clouds?
• Clouds are condensation (gas to liquid)
– visible masses of tiny water, ice, or supercooled
water droplets in the air.
• Supercooled water is water droplets that
remain in the liquid state at temperatures well
below 0oC.
Weather Jokes
Q: What did the male raindrop say to the
beautiful female raindrop?
A: I'm falling for you
18.3 How do clouds form?
 Expansion and Cooling
• Most clouds form from air that rises.
18.3 How do clouds form?
 Expansion and Cooling
• Air that rises expands and cools
• For clouds to occur air must be saturated.
• When air reaches or equals the dew point.
Weather Jokes
Q: What do you call a sheep with no legs?
A: A cloud.
18.3 Cloud Types
 Clouds are classified on the basis of their:
• form (shape) and height (altitude).
18.3 Cloud Prefixes
 Prefixes:
• Cirr = high-altitude clouds
•
Clouds are white
• Alto = mid level cloud
•
Clouds are white tops and gray bottoms
• Nimbo = meaning precipitation
Main Cloud Type - Cirrus Clouds
• prefix cirr = high
• cirrus = curl of hair
• are clouds that are
high, white, thin, and
wispy.
Main Cloud Type - Stratus Clouds
• stratus = a layer
• Are clouds best
described as sheets
or layers that cover
much or all of the sky.
• Flat gray cloud
Cloud Type - Stratus Clouds
• flat rain cloud
• Stratus + nimbus
• nimbostratus
Main Cloud Type - Cumulus Clouds
• cumulus = a pile
• Are clouds that
consist of rounded
individual cloud
masses.
• Puffy cloud
Cloud Type - Cumulus Clouds
• puffy rain cloud
• Cumulus + nimbus
• cumulonimbus
Cloud Classification
18.3 Fog
 Fog is defined as a cloud at or very near the ground.
• Fog is a stratus cloud
18.3 Fog
 Fog occurs when the air near the ground is
saturated by:
• Cooling the air
• Cause by evaporation – adding moisture
April 4, 2011 (7a.m.)
Ch 18.3 Clouds
• Objective: Be able to…
– Identify different types of clouds based on
their height and form.
– Define how clouds form
Fluffy, shape forming clouds that have a base and
then extend upwards from that base.
Cumulus
An ice crystal cloud showing filaments of ice
crystals precipitating and evaporating
Cirrus
A low, flat layer cloud that looks as if it is going to
rain. Darker gray and usually brings light
precipitation.
Nimbostratus
A very large, usually anvil-shaped cloud
associated with thunderstorms.
Cumulonimbus
Low, gray layer cloud that covers most or all of the
entire sky. Often looks like a layer of fog that was
lifted off the ground.
Stratus
low-level stratus: a cloud that touches the ground
Fog
Typically a portion of this cloud is shaded, a characteristic
which makes them distinguishable from the high-level
cirrocumulus.
Altocumulus
High level veil of ice crystal cloud, frequently
producing a halo around Sun or Moon
cirrostratus