Transcript cloud types - Junction Hill C

Cirrus Clouds thin and wispy The most common form of
high-level clouds are thin and often wispy cirrus clouds.
Typically found at heights greater than 20,000 feet,
cirrus clouds are composed of ice crystals. Cirrus
generally occur in fair weather and point in the
direction of air movement at their elevation.
Cirrostratus Clouds sheet-like
and nearly transparent
Cirrostratus are sheet-like,
high-level clouds composed
of ice crystals. Though
cirrostratus can cover the
entire sky and be up to
several thousand feet thick,
they are relatively
transparent, as the sun or the
moon can easily be seen
through them. Sometimes the
only indication of their
presence is given by an
observed halo around the sun
or moon.
• Cirrocumulus
clouds appear as
small, rounded
white puffs. The
small ripples in the
cirrocumulus
sometimes
resemble the
scales of a fish. A
sky with
cirrocumulus
clouds is
sometimes referred
to as a "mackerel
sky."
Altocumulus Clouds
These clouds may appear as
parallel bands or rounded masses.
Typically a portion of an
altocumulus cloud is shaded, a
characteristic which makes them
distinguishable from the high-level
cirrocumulus. Altocumulus clouds
result from the gradual lifting of
air in advance of a cold front. The
presence of altocumulus clouds on
a warm and humid summer
morning is commonly followed by
thunderstorms later in the day.
Altostratus clouds are gray or blue-gray middle level
clouds composed of ice crystals and water droplets.
These clouds usually cover the entire sky. In the
thinner areas of the cloud, the sun may be dimly
visible as a round disk. Altostratus clouds often form
ahead of storms that will produce continuous
precipitation.
Stratus clouds are uniform grayish clouds that often
cover the entire sky. They resemble fog that does not
reach the ground. Usually no precipitation falls from
stratus clouds, but sometimes they may drizzle. When a
thick fog "lifts," the resulting clouds are low stratus.
Nimbostratus Clouds are dark, low-level clouds
accompanied by light to moderately falling precipitation.
Low clouds are primarily composed of water droplets
since their bases generally lie below 6,500 feet. However,
when temperatures are cold enough, these clouds may also
contain ice particles and snow.
Stratocumulus Clouds generally appear as a low, lumpy layer
of clouds that is sometimes accompanied by weak intensity
precipitation. Stratocumulus vary in color from dark gray to
light gray and may appear as rounded masses, rolls, etc., with
breaks of clear sky in between.
Fair Weather Cumulus Clouds have the appearance of
floating cotton and have a lifetime of 5-40 minutes. Known
for their flat bases and distinct outlines, fair weather cumulus
exhibit only slight vertical growth, with the cloud tops
designating the limit of the rising air.
When the top of the
cumulus resembles the
head of a cauliflower, it
is called cumulus
congestus or towering
cumulus. These clouds
grow upward, and they
can develop into a giant
cumulonimbus, which is
a thunderstorm cloud.
Cumulonimbus Clouds are much larger and more vertically
developed than fair weather cumulus. They can exist as
individual towers or form a line of towers called a squall line.
Fueled by vigorous convective updrafts, the tops of
cumulonimbus clouds can easily reach 39,000 feet or higher.