“A visible collection of CONDENSED
tiny water droplets and ice crystals suspended
in the atmosphere.”
Clouds can be in variety of forms.
Some are found at high elevation but other
are near the ground relatively
occurs due to
Water is known to exist in three forms:
Clouds, snow and rain are all made up of
some form of water.
Generally produced by atmospheric motion with
upward component cools the air.
Clouds form when temperature is below the dew
When air blows over the colder surface.
By orographic uplift of air near the mountainous
Air parcel will rise up naturally if the air
within it is warmer than the surrounding air by
Clouds are classified into a system that uses
“Latin” words to describe their appearances.
They are define on the basis of their
This was done by an English chemist “Luke
Howard” in 1803.
HOWARD divided them into 4 categories
using Latin names as:
Curl of hair
They are further divided into 4 groups having 10
types of the clouds:
Vertically Developed Clouds
The first 3 groups are differentiating by their heights.
The fourth group contains thick clouds as they are
NOT describe on the basis of heights level from
are due to unstable atmospheric
Height can range up to 12000m.
Generated most commonly either by
thermal convection or frontal lifting.
Releasing incredible amount of energy to
condensed the water vapor within the clouds.
generally not the
sign of calm
Vertically developed clouds are more
conveniently divided into 2 categories as:
i. Cumulus Humilis Clouds
ii. Cumulus Fractus Clouds
iii. Cumulus Congestus Clouds
iv. Cumulus Constellus Clouds
i. Cumulonimbus Incus Clouds
ii. Cumulonimbus Mammatus Clouds
iii. Cumulonimbus Calvus Clouds
They look like white ball of cotton _ isolated in sky.
Are sign of pleasant weather.
They have flat bottoms and lumpy tops.
Top often is in the form of towers--- shows the limit
of rising air.
Rising air is associated with high relative humidity.
Generally they are formed by convection resulting
from solar heating in summers.
Over open lakes in autumn and winters.
They are found as low as 330ft.
Humilis stands for “HUMBLE.”
Generally have flattened bases and slight vertical
Mostly rises up to 5-8km.
Once the thermals rise above the surface, the
potential for cloud development increases.
At the condensation level, the relative humidity of
the thermal air will be around 100 percent (saturated).
Between each cumulus humilis, the air descends slowly
to replace the rising thermals
Cumulus clouds that appear in irregular
fragments, as if they had been shred or torn.
Always appear in
association with other
For a short time
before, during and a
short time after
They can form in fair weather as rising pockets of
warm air rise and condense into these proto-clouds
Cumulus fractus on
days, too, as they
"shredded" by larger
after a rain storm
Congestus is Latin for "piled-up".
When a humilis cloud grows vertically
it turns into a congestus cloud.
It stands for “Castle-like”.
It displays multiple towers
arising from its top, indicating
significant vertical air
These clouds are named because they are puffy
("cumulo") and because they often are dark clouds
which cause rainstorms ("nimbus").
Cumulonimbus clouds are characterized
as tall, dense clouds
These are more vertically developed than fair
weather cumulus and have tops that can reach up to
39,000 feet (12,000m).
These are fueled by strong updrafts that transfer air
up through the atmosphere.
Cumulonimbus clouds designs
its formation mostly during the
afternoon time, as this the time
when the earth surface gets
Cumulonimbus clouds are
usually seen in the shape of
Common types of Clouds
Cumulonimbus Cloud Over Africa
March 24, 2011
Image Credit: NASA
Incus stands for “Anvil”.
A mature cumulonimbus incus is definitely the
“King of Clouds”, and sometimes reaching 60,000 feet
in tropical and subtropical areas.
Formation always be regarded as a significant
aviation hazard because of :
“the powerful air currents involved in its formation and
the potentially damaging effect of the large hailstones it
They look like “BAG.”
Mammatus is one of the most spectacular and
distinctive of all cloud formations.
During a thunderstorm, warm, moist updrafts rise to
the top of the troposphere. Here the temperature levels
off and the air stabilizes. This causes the rising cloud to
expand horizontally over areas of cooler, cloud-free air.
m for rain
Calvus stands for “Bald”.
Calvus occurs when convection and atmospheric
instability combine to push the cloud tops beyond the
congestus stage to heights of up to 30,000 feet.
The mushrooming top is a sign
of the vigorous updrafts that may
eventually force the cloud up into
the highest levels of the
At this level of the
troposphere, temperatures are
normally well below freezing, and
any condensation that takes place
will produce ice crystals rather
than water droplets.
This gives the top of the cloud a
brilliant, white appearance.