Low Altitude Clouds
 Form below 2000 meters.
 Forms when warm, moist air rises, expands
and cools.
 Made of water droplets only!
 There are 5 different types of clouds here.
Cumulus Clouds
 They are often described as "puffy" or
"cotton-like", or "poofy" in appearance.
 Cumulus clouds can appear alone, in lines, or
in clusters (groups).
 They may be associated with severe weather
such as hail and tornadoes (cumulonimbus)
but often mean fair, sunny weather
Cumulus Clouds
Stratus Clouds
 Layered, sheet-like clouds.
 These clouds are layered horizontally (left to right).
 More specifically, the term stratus is used to describe
flat, hazy, plain looking clouds.
 Can vary from dark gray to nearly white in terms of
color.
 Can bring a small amount of precipitation with them.
Stratus Clouds
Stratocumulus Clouds
 Usually characterized by large dark, rounded
masses of clouds – found in in groups or lines.
 These clouds usually produce NO
precipitation, but are often seen at the
beginning or end of a front (before or after a
storm).
 These clouds appear very large in the sky to
the people who are viewing them.
Stratocumulus Clouds
Fog – A cloud on the ground.
 Fog reduces visibility for driving or flying
conditions.
 The foggiest place in the world is the Grand
Banks off the island of Newfoundland.
 The foggiest land areas in the world are
Menomonie, Wisconsin, Point Reyes,
California, and Argentia.
Fog
Nimbostratus Clouds
 A Nimbostratus cloud has no distinct shape
to it and is almost uniformly dark gray all
over.
 "Nimbo" is from the Latin word "nimbus",
meaning rain.
 These clouds are dark because they are storm
clouds!
Nimbostratus Clouds
Middle Altitude Clouds
 Form between 2000 – 6000 meters above
Earth.
 Made of water droplets and ice crystals
because the air is colder at these altitudes.
 Some middle altitude clouds can form
precipitation.
 There are 2 main types of clouds here.
Altocumulus Clouds
 These types of clouds appear in sheets, patches
or bunched together.
 They are usually larger and appear white or grey
in color.
 Altocumulus clouds shows that convection is
occurring in the atmosphere.
 May also cause rain if they are high enough in
the atmosphere.
Altocumulus Clouds
Altostratus Clouds
 These clouds are usually lighter in color and
almost transparent - so sunlight can often be
seen through them.
 They frequently cover the whole sky and are
similar to lower altitude stratus clouds.
 Altostratus clouds can be potentially dangerous,
because they can cause ice to build up on the
wings of an airplane.
Altostratus Clouds
High Altitude Clouds
 Form higer than 6000 meters above Earths
surface.
 Made of ice crystals only because the
temperatures at this height are below
freezing.
 There are 4 types of clouds here.
Cirrus Clouds
 Cirrus clouds are characterized by a thin,
wispy look to them. Almost like strands of
string in the sky.
 Many cirrus clouds produce a small amount of
precipitation (ice crystals) that are suspended
in the air and do NOT reach the ground.
Cirrus Clouds
Cirrostratus Clouds
 These types of clouds never bring precipitation with them
and have a thin, whitish, veil-like structure (just like cirrus
clouds).
 Sometimes these clouds are so big that you cannot tell
them apart from one another (they blend in).
 Can form a halo, which is a glowing look that surrounds a
cloud when sunlight hits the water vapor within the cloud.
 Cirrocumulus clouds usually do not last long and could carry
small amounts of precipitation along with them (mostly ice
because it is very cold at this altitude).
Cirrostratus Clouds
Cirrocumulus Clouds
 Forms when convection currents at high
altitudes mix to produce a cirrocumulus
cloud.
 These are usually very large clouds that
include droplets of super cooled water in
them, allowing ice crystals to form.
Cirrocumulus Clouds
Cumulonimbus Clouds
 A tall, dense cloud that carries along thunderstorms
and other intense weather conditions.
 Cumulonimbus means "column of rain“ – so
precipitation will always be involved.
 These clouds can form alone, in clusters, or along a
cold front.
 They create lightning through the center of the
cloud and if conditions are right can further develop
into a super cell, which is a severe thunderstorm .
Cumulonimbus Clouds