Clouds, It's Types and Their Classification

Cloud:
Cloud can be defined as a mass of tiny water droplets ice crystals OR both condensed on hygroscopic nuclei and suspending in the atmosphere.

Clouds and fogs are composed of water droplets or ice crystals or both of the order of size 20 to 60 microns (0.008-0.024 millimeter).

Isoneph:
Lime joining places of equal clouds cover on a map is known as isoneph.

Principles of cloud classification :

The great variety of cloud forms necessitates a classification of weather reporting. The internationally adopted system is based upon (a) The general shape; structure and vertical extend of the clouds and (b) their altitude.
Types of clouds: There are four basic types of clouds:
1. Clrrus (CI):
Meaning “cur” and is recognized by its veil, like fibrous or featery form.  It is the highest type of cloud, ranging from approximately 7-12 km in altitude. (20,000 to 35,000 feet).

2.  Cumulus (Cu):
Meaning “heap”, is the wooly, bundly cloud with rounded top and flat base.  It is the most common in the summer season and in latitudes where high temperature prevail and it always results from convection Its height is variable and depends on relative humidity of the air.

3.   Stratus (St):
It is a sheet type cloud without any form to distinguish it.  It is usually lower than cumulus.

4. Nimbus (Nb):
It is any dark and ragged cloud and from which precipitation occurs.

Classification Of Clouds
Clouds have been classified according to their height and appearance by world Meteorological organization (WHO) into 10 categories.

Cloud family and Height	Name of cloud and abbreviation	Composition	Possible weather change	Description and appearance
1	2	3	4	5
Family A High clouds 7 to 12 km	1 Cirrus (Ci)	Ice crystals	May Indicate storm showery weather	It is wispy and feathery, sun shines without shadow.  It does not produce precipitations
	2. Cirrocumulus (CC)	Ice crystals	Possible storm	Meekerel sky, often fore renners of cyclone, look like sippled sand
	3. Cirrostratus(Cs)	Ice crystals	Possible storm	Meekeral sky, often fore runners of cyclone, look like sippled sand.
Family B middle clods 3 3-7 km	4. Altocumulus (As)	Ice & water	Steady rain or snow	Looks like wool peak, sheep bulk clouds.
	5. Atmostratus (As)	Water and ice	Impending rain or snow	Fibrous veil or sheet, grey or bluish, produce coronos, usually ct.st shadow.
Family C low clouds from ground to km	6. Stratocumulus (Se)	Water	Rain possible	Long parallel rolls, pushed together or broken masses which look soft and grey but with darker parts, air is smooth above but strong updrafts occur below.
	7. straus (St)	Water	May produce drizzle	A low uniform layer, resembling fog, but resting not on the ground, chief winter cloud.
	8.Nimbostrauts	Water or Ice	Impending rain or snow	Fibrous veil or sheet, grey, grey or bluish produce coronas, usually
Family D clouds with vertical development from 0.5 to 16 km	9.Cumu-lus (Cu)	Water	Fair weather	Looks like wool pack, dark below due to shadow, may develop into cumulous –Nimbus flat base.
	10, Cumulous –Nimbus (Cb)	Ice in upper level and water in lower level.	Violet winds rain, all possible thunderstorm hail lighting possible	Thunder head, towering anvil top, violet up and down drafts, aviators avoid them, develop from cumulus, chief precipitation makers.
	10 cumulo-Nimbus(Cb)	Ice in upper level and water in lower level	Violet winds rain, all possible thunderstorm hail lighting  possible	Thunder head, towering anvil top, violet up and down drafts, aviators avoid them, develop from cumulus chief precipitation makers.