Chapter 6, Part 2

Clouds

Major Cloud Groups and Types

High clouds

Cirrus (Ci)

Cirrostratus (Cs)

Cirrocummulus (Cc)

Middle clouds

Altostratus (As)

Altocummulus (Ac)

Low clouds

Stratus (St)

Stratocummulus (Sc)

Nimbostratus

Clouds with vertical development

Cummulus (Cu)

Cummulonimbus (Cb)

Cirrus Clouds

Wispy clouds blown by the wind into long streamers

Generally point to fair weather

Like other high clouds composed largely of ice crystals

Cirrocummulus Clouds

Small rounded white puffs which occur individually or in rows

Seldom cover the entire sky

Cirrostratus Clouds

Thin sheets of clouds

Often cover entire sky

Sun and moon visible through them

Altocummulus Clouds

Gray and puffy, sometimes in parallel bands

May indicate later thunderstorms

Composed mostly of water droplets and some ice, depending on temperature

Altostratus Clouds

Gray or blue-gray cloud

Often covers entire sky

Composed of ice and water

Nimbostratus Clouds

Dark gray cloudy layer

Continuous light to moderate rain or snow

Stratocummulus Clouds

Low lumpy clouds with blue sky visible between them

Stratus Clouds

Uniform grey cloud that covers the entire horizon

Usually no precipitation, but may be mist or drizzle

Cummulus Clouds

Looks like floating cotton with a flat base

Blue sky visible between them

Cummulonimbus Clouds

Thunderstorm cloud

Large vertical extent, e.g., 600m - 10,000m

Isolated or part of a line of clouds

Illustration of Basic Cloud Types

Determining Sky Conditions

Satellite Observations

Summary

Clouds are classified by height and vertical structure into four groups.

There are ten basic cloud types, which you should know.


	High clouds
		Cirrus (Ci)
		Cirrostratus (Cs)
		Cirrocummulus (Cc)
	Middle clouds
		Altostratus (As)
		Altocummulus (Ac)
	Low clouds
		Stratus (St)
		Stratocummulus (Sc)
		Nimbostratus
	Clouds with vertical development
		Cummulus (Cu)
		Cummulonimbus (Cb)


	Wispy clouds blown by the wind into long streamers
	Generally point to fair weather
	Like other high clouds composed largely of ice crystals


	Small rounded white puffs which occur individually or in rows
	Seldom cover the entire sky


	Thin sheets of clouds
	Often cover entire sky
	Sun and moon visible through them


	Gray and puffy, sometimes in parallel bands
	May indicate later thunderstorms
	Composed mostly of water droplets and some ice, depending on temperature


	Gray or blue-gray cloud
	Often covers entire sky
	Composed of ice and water


	Dark gray cloudy layer
	Continuous light to moderate rain or snow


	Uniform grey cloud that covers the entire horizon
	Usually no precipitation, but may be mist or drizzle


	Looks like floating cotton with a flat base
	Blue sky visible between them


	Thunderstorm cloud
	Large vertical extent, e.g., 600m - 10,000m
	Isolated or part of a line of clouds


	Clouds are classified by height and vertical structure into four groups.
	There are ten basic cloud types, which you should know.