Cloud type

Cloud type

Following the official classification of the World Meteorological Organisation (WMO) there are
10 different cloud types. These can be divided further into subtypes. Here you find a description of the 10 cloud
types.

Cirrus

form

Thin fibres or threads, rarely also bundles; edges usually frayed by the high winds.

description

consist of ice crystal .

interpretation

Fair weather clouds; when compressed it can be a sign of a warm front (precipitation).

altitude:

8 – 12 km

precipitation:

none

meteoblue description:

Cirrocumulus

form

Heap clouds; occur mostly in more or less expanded fields, which consist of small granular
cloud parts, rarely also in small ripped to pieced bundles.

description

Consist almost exclusively of ice crystals; strongly undercooled water drops will mostly
freeze inside the cloud.

interpretation

indicate strong vertical movement in the altitude in which they form .

altitude:

8 – 12 km

precipitation:

none

meteoblue description:

Cirrostratus

form

Layer clouds. Occur either as a fibrous veil in which thin stripe can form, or as a
veil-like fog; they can never completely cover the Sun. Under certain conditions, these clouds produce a “halo” around the Sun, caused by the
refraction of the sunlight.

description

Consist primarily of small ice particles.

interpretation

Indicate the arrival of a warm front (with precipitation) within 1 to 2 days.

altitude

8 – 12 km

precipitation

none

meteoblue description

Altocumulus

form

Heap clouds; appear mostly as a big field which consists of many small single clouds.

description

Consist almost exclusively of water droplets; only at low temperatures ice-crystals can
appear.

interpretation

Indicate horizontal aerial current and, in addition, vertical currents at some places in the
middle cloud layer.

altitude

2 – 8 km

precipitation

none

meteoblue description

Altostratus

form

Thread medium high layer clouds without contours.

description

Composed of ice-crystals as well as water droplets.

interpretation

Indicator for precipitation within the next few hours.

altitude

2 – 8 km

precipitation

rain or snow

meteoblue description

Stratocumulus

form

shallow – layer clouds is appears without fibre ; appear in spot , field or layer which aggregate into
steadily arrange cloud , bale or roll .

description

Consist primarily of water droplets; these are the most frequent clouds; often have grey
colouring, because the water droplets absorb a lot of light.

interpretation

Generally annunciates an instability of the atmosphere. Takes place just before an occlusion
between a cold front and a warm front.

altitude

0,6-2 km

precipitation

sometimes rain or snow

meteoblue description

Stratus

form

Low-layer clouds, also described as high fog or above-ground fog; absolutely without
structure.

description

Consist of small water droplets; they can generate halos; often originate with high pressure
and low air movement.

interpretation

generally indicate a rather quiet weather condition .

altitude

0 – 2 km

precipitation

often sprinkling of rain

meteoblue description

Cumulus

form

Cumulus are thick heap cloud sharply separate from each other ; the edges is look sometimes look
tattered and change constantly .

description

Consist almost exclusively of water droplets; ice-crystals can only appear at low
temperatures; originate with locally restricted upward wind; for gliders and pilots, cumulus are an indicator
for upward winds.

interpretation

Nice weather clouds. If the clouds reach the medium levels of the atmosphere and is turning
into a cumulonimbus cloud, light showers may arrive.

altitude

0,6-2 km

precipitation

seldom

meteoblue description

Nimbostratus

form

Very vast , dark grey layer ; strong vertical expansion

description

Consist of water droplets and/or ice-crystals; originate from the upward movement of moist
air moving within a warm front.

interpretation

Long-term rain/snow for several hours or days.

altitude

0,6-12 km

precipitation

rain or snow

meteoblue description

Cumulonimbus

form

Very big heap clouds with a massive vertical expansion originating from a cumulus cloud.

description

Consist of water droplets and ice-crystals which however primarily appear in the upper
parts. Originate from a big cumulus cloud which, if it contains enough humidity and elevation impulses, expands
in altitude. Later, the upper part of the cloud still expands, and give the so-called “anvil” cloud.

interpretation

Cumulonimbus precipitation falls in the form of rain, hail or snow, thunderstorms are often
also present; a full-grown cloud can take up up to 100 million tons of water, hence, violent showers and hail
can fall. Moreover, violent hoists which can reach a speed from up to 120 km/h are to be calculated on with
cumulonimbus. Within the cloud, there is also strong turbulences, so that they can themselves become dangerous
for big airplanes and should therefore be flown around.

altitude

0,6-12 km

precipitation

strong precipitation , often with thunderstorm

meteoblue description

Here you can see the forecast pictocasts for 3 places where you can find frequent thunderstorms – and thus frequent clouds. Compare the meteoblue representation of the cloud types with
the forecast. Can you already have a good idea of the weather in Kinshasa, Manaus or Djakarta? Do you also see which
clouds mainly cause the precipitation?