Cloud formationInquiry: What, how, and why?

A cloud is a large collection of very tiny droplets of water or ice crystals. The

droplets are so small and light that they can float in the air!

What are Clouds?

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 forms a tiny droplet around each

dust particle. When billions of these droplets come together they become a visible cloud!

How are clouds formed?

Rising Air• Imagine a block of air (air parcel) rising

upward through the atmosphere. • As the air parcel rises it expands!• This expansion causes the temperature of the

air parcel to decrease.

Rising Air• Imagine a block of air (air parcel) rising

upward through the atmosphere. • As the air parcel rises it expands!• This expansion causes the temperature of the

air parcel to decrease.

Condensation

• As the block of air rises the atmosphere is cooler.

• Cold air holds less water than hot air, therefore, the water vapor gets closer (condenses) & cloud droplets form!

Formation…• This can happen through many different ways– Convection Currents– Lifting– Frontal Activity

Convection Currents

Lifting (help of mountains)

Frontal Activity (Warm & Cold)

Clouds are made up of tiny water droplets or ice crystals, usually a mixture of both. The water and ice scatter all light, making clouds appear white.

However, If the clouds get thick enough (too much water vapor) all the light above does not make it

through, hence the gray or dark look

Why do clouds turn gray?

A cloud is made up of liquid water droplets. A cloud forms when air is heated by the sun. As

it rises, it slowly cools it reaches the saturation point and water condenses,

forming a cloud. As long as the cloud and the air that its made of is warmer than the

outside air around it, it floats!

Why do clouds float?

Clouds move with the wind. High cirrus clouds are pushed along by the

jet stream, sometimes traveling at more than 100 miles-per-hour. When

clouds are part of a thunderstorm they usually travel at 30 to 40 mph.

How do clouds move?

What are the different types of clouds?

There are many different types of clouds and different ways to identify them. This type of

identification classifies clouds by the height of the cloud base.

• High Level Clouds• Mid-Level Clouds• Low-Level Clouds

• Miscellaneous Clouds

• HIGH ALTITUDE CLOUDS:• Cirrocumulus – Puffy, patchy look with spaces• Cirrostratus – light gray or white, thin, covers

most of the sky. • Cirrus – thin wispy and feathery appearance

High Altitude clouds ...Cirrus clouds are ice clouds. They can look like delicate white feathers or streamers. They are always more than five kilometers up where the temperature is below freezing, even in summer! Wind currents twist and spread the ice crystals into wispy strands.

• MIDDLE ATLTITUDE CLOUDS:• Altocumulus – puffy, patchy look with spaces• Altostratus – light gray and uniform in

appearance. Covers most of the sky.

• LOW ATITUDE CLOUDS:• Cumulus – puffy, looks like cotton balls/popcorn• Stratus – light/dark gray and uniform. Fog!• Stratocumulus – irregular masses, rolling or puffy with

spaces.• Nimbostratus – dark gray with precipitation falling from

them. Bases are hard to see b/c of rain.• Cumulonimbus – large clouds w/ dark bases and tall

billowing towers. Also known as “Thunder Clouds”

LOW ATITUDE CLOUDS (close up)

LOW ATITUDE CLOUDS (close up)

LOW ATITUDE CLOUDS (close ups)

Cumulonimbus clouds…

…are a sure sign of bad weather -Rain, thunder, lighting, hail, and possibly tornadoes!