Clouds

What are they?How do they form?

What types are there?

What is a cloud?A visible collection of water droplets or frozen

crystals of water that are suspended above the surface of the earth.

How are clouds formed?All air contains water, but near the ground it is

usually in the form of an invisible gas called water vapor. When warm air rises, it expands and cools. Cool air can’t hold as much water vapor as warm air, so some of the vapor condenses onto tiny pieces of dust that are floating in the air and form as a tiny droplet around each dust particle. When billions of these droplets come together they become a visible cloud.

Why are they white?They are white because they reflect the light of the

sun

Cloud PrefixesHigh Clouds

Middle Clouds

Cirro = clouds above 18,000 feet

Alto =6,500 fee to 18,000 feet above ground

Strato = Ground level to 6,500 feet

Low Clouds

Cloud Prefixes are:

Cirro is for High Clouds

Alto is for Middle Clouds

Strato is for Low Clouds

Types of cloudsCUMULUS: CUMULUS: Latin word meaning heap

White puffy clouds Seen on a sunny day, the wind blows them aroundThese are the clouds you can see shapes in

Cumulus clouds

Notice the blue sky, white puffy clouds

Can you see an animal in the cloud in the center? I can

Types of Cumulus CloudsCirrocumulus Clouds

Small rounded white puffs that appear in long rows. Small ripples sometimes resemble the scales of a fish. Usually seen in winter and indicate fair, but cold weather. In tropical regions them may indicate an approaching hurricane.

Types of Cumulus cloudsAlto Cumulus = mid level clouds made of water

droplets and appear as gray puffy masses. If you see them on a warm sticky summer morning, be prepared to see thunderstorms in the late afternoon.

Types of Cumulus cloudsStratocumulus Clouds = low, puffy and gray,

most are in rows with blue sky between. Rain rarely occurs with stratocumulus clouds.

Types of cloudsSTRATUSSTRATUS: Latin root means layered

Usually seen on a rainy dayLike a blanket of light gray in the skyYou can’t tell where one cloud ends and another begins

Stratus Clouds

Notice how it looks like a blanket? Some of the clouds are lighter than others.

Types of stratus clouds

Thin sheetlike high clouds that often cover the entire sky. Usually come 12-24 hours before snow or rain.

Cirrostratus

Altostratus CloudsGray or blue-gray mid-level cloudsUsually cover the entire skyForm ahead of storms with continuous rain or snow

How are these clouds different?Cumulus clouds Stratus clouds

Cloud types Cirrus CloudsCirrus Clouds

Thin and wispyHigh in the skyMade of ice crystalsSeen on a fair dayPoint or curl in the direction the wind is movingUsually indicate a change in the weather within 24

hours

Cirrus Clouds

See how you can almost see through these clouds? They also have “tails” that point in the direction the air is moving (what is moving air called?)

Types of cloudsNimbus Nimbus (latin means cloud)

Is giving off rain or snow (what is this called?)Dark gray Usually cover the whole skyCan produce a thunderstorm or tornado

Nimbus Clouds

You can see how dark they are. Sometimes they are not quite so dark, but they usually have rain or snow with them.

How are these different?Nimbus clouds Stratus clouds

How are these clouds different?Cumulus clouds Cirrus clouds