CLOUDS AND
ASSOCIATED WEATHER
Name
Class
DIRECTIONS: Using the references provided:
Add sketches, abbreviations, high, low or middle cloud, and symbols to the
following chart. In the last column write down any typical weather generally
associated with a particular cloud.
CLOUD
High, Low,
or Middle?
SKETCH
SYMBOL
ABBREV.
Altostratus
Altocumulus
Cirrus
Cirrostratus
Cirrocumulus
Cumulus
Cumulonimbus
Stratus
Nimbostratus
Stratocumulus
© Copyright 2010.! M. J. Krech. All rights reserved.
Associated
Weather?
Clouds, Abbreviations and Associated Weather
-----------------------------------------------------------------------1. Cirrus - Ci
a. Characteristics
High white delicate cloud. Composed of ice crystals. Always white (except possibly after
sunset or before sunrise). Often a sign of a change in the weather.
b. Weather prediction
Small amounts of cirrus are OK but lots of dense cirrus is often a sign of storms to come.
c. Precipitation
None.
------------------------------------------------------------------------
2. Cirrocumulus - Cc
a. Characteristics
Very small, white clouds. Sometimes a 'mackerel sky' but this is more often formed with
altocumulus.
b. Weather prediction
Real cirrocumulus is a sign of storms on the way.
c. Precipitation
None.
-----------------------------------------------------------------------3. Cirrostratus - Cs
a. Characteristics
Thin white clouds, very high in the atmosphere. Can be difficult to see at first - a 'halo'
around the sun is often a giveaway.
b. Weather prediction
Almost certain predictor of a warm front. Continuous rain in a few hours, but not
generally stormy.
c. Precipitation
None.
-----------------------------------------------------------------------4. Altocumulus - Ac
a. Characteristics
Medium level 'lumps' of cloud. Great for sunset photography. Often forms a 'mackerel sky.’
b. Weather prediction
Altocumulus means unsettled and possibly stormy weather to come.
c. Precipitation
Very rare.
-----------------------------------------------------------------------5. Altostratus - As
a. Characteristics
Light gray formless sheet of medium level cloud. The sun will sometimes appear as through
ground glass. The loss of the halo signifies altostratus has replaced cirrostratus as the
warm front approaches yet nearer.....
b. Weather prediction
Approach of warm front imminent. Get the umbrella ready.
c. Precipitation
Precipitation sometimes in the form of continuous light rain.
© Copyright 2010.! M. J. Krech. All rights reserved.
6. Nimbostratus - Ns
a. Characteristics
Dense gray-blue cloud.
b. Weather prediction
Too late for predictions - sorry.
c. Precipitation
Heavy continuous rain associated with passing warm front
-----------------------------------------------------------------------7. Stratocumulus - S c
a. Characteristics
Low level, almost con tinuous layer of cloud, but 'lumpy'. Can be formed as cumulus or
sometimes cumulonimbus fades away (usually in the evening).
b. Weather prediction
Normally a dull period. There are different forms of stratocumulus which makes forecasting
difficult without a lot of knowledge. It can accompany 'high pressure' in the winter, but
instead of weak winter sunshine, can give an extensive cover of cloud for days on end.
c. Precipitation (rain/snow etc.)
Not normally rain - but drizzle sometimes (a word of warning - drizzle relates to the size of
droplet). Heavy drizzle (lots of small diameter bits of precipitation) can get you wet on
occasion.
-----------------------------------------------------------------------8. Stratus - St
a. Characteristics
Fog and mist are examples of this low level cloud - no form.
b. Weather prediction
Cold if it persists in Winter - Otherwise not a reliable predictor.
c. Precipitation (rain/snow etc.)
None. (but beware - there may be something else above!).
-----------------------------------------------------------------------9. Cumulus - Cu
a. Characteristics
Low level 'lumpy' cloud.
b. Weather prediction
Small cumulus (with a height to width ratio less than 1:3 is sometimes called 'fair-weather'
cloud.
c. Precipitation (rain/snow etc.)
Showers sometimes (but more extensive rainfall in the tropics).
------------------------------------------------------------------------
10. Cumulonimbus - Cb
a. Characteristics
Large towering cloud, often with an 'anvil'. Other characteristics: Thunder, lightning,
rainbows.
b. Weather prediction
Time to get indoors
c. Precipitation (rain/snow etc.)
Rain, hail etc.
© Copyright 2010.! M. J. Krech. All rights reserved.
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WEATHER FORECASTING CLOUD CHART
Altocumulus
Good weather. Absence of
winds means good weather
will continue
Altostratus translucidus
Precipitation likely in 10 to
15 hours if winds steady NE
to S. Sun appears to be
behind frosted glass. Other
winds bring overcast sky.
Stratus
Winds from NE to S may
bring heavy precipitation.
Other winds may bring only
a light drizzle or overcast
sky
Cirrostratus covering sky
Ice Clouds cover sky.
Precipitation likely within
15-25 hours if winds steady
from NE E to S, or sooner
if winds SE to S. Other
winds bring overcast sky.
Cirrocumulus
Ice Clouds. Precipitation is
likely 15-20 hours if wind
NE to S, often afternoon
thunderstorms. Other winds
overcast
Nimbostratus
Rain or snow clouds.
Precipitation of long
duration if winds NE to S,
or shorter duration if winds
are SW W to N
Cumulus with vertical
growth
Fair weather clouds building
up vertically often indicate
cumulus congestus and
cumulonimbus, which bring
afternoon showers
Cumulonimbus
Precipitation likely and soon
coming usually from SW W
to N. Distant clouds often
show an anvil-shaped
cirroform cap
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