Lesson 2: Types of Clouds

Clouds come in many shapes and forms. Some are high in the sky, while others are so low they touch the ground. No matter what shape or elevation, clouds form the same way, by having water vapor condense onto small solid particles like dust, sea salt, and pollution.

Clouds serve several important functions. One of these is providing rain and snow. They also help retain heat, so it doesn’t escape quickly back into space. On hot days, clouds provide shade

There are three main cloud types.

Cumulus clouds are the puffy clouds that look like puffs of cotton. Cumulus clouds that do not get very tall are indicators of fair weather. If they do grow tall, they can turn into thunderstorms. The bottom of cumulus clouds are fairly close to the ground.

Stratus clouds look like flat sheets of clouds. These clouds can mean an overcast day or steady rain. They may stay in one place for several days.

Cirrus clouds are high feathery clouds. They are up so high they are actually made up of ice particles. They are indicators of fair weather when they are scattered in a clear blue sky.

Nimbus is another word associated with clouds. Adding "nimbus" means precipitation is falling from the cloud.

Cumulonimbus clouds are the "thunderheads" that can be seen on a warm summer day and can bring strong winds, hail, and rain.

Nimbostratus clouds will bring a long steady rain.

Activity One – Create A Cloud

Materials: A large clear plastic jar, a small metal tray, ice cubes, and hot water.

Setting Up the Activity: Fill the plastic jar about 1/2 full of hot water. Place some ice cubes on the metal tray, and place the tray on top of the jar.

Questions:

Q. What happens inside the jar?

A. A "cloud" should form directly underneath the tray.

Q. Why does this happen?

A. Air and water vapor inside the jar next to the tray is cooled, condensing into water droplets.

Q. How does this compare to how real clouds are formed?

A. In the atmosphere, air rises, cools, and water vapor present in the air condenses into clouds.

Activity Two – Make A Cloud Collage

Materials: Posterboard, paper, glue, magazines with clouds pictures (that can be used for cutouts), or a camera with film to take pictures.

Setting Up the Activity: Make a collage of as many different types and sizes of clouds as possible. This can also be done as a group activity. Record the type of weather associated with each cloud, such as fair, rainy, warm, or cold. The clouds can also be divided into types of cumulus, stratus, or cirrus.

Questions:

1. What type of weather was found with each cloud?
   
2. What direction were most of the clouds moving from?
   
3. How long was it before the weather changed, (cleared up, started raining, got warmer/colder?)
   
4. What main types of clouds were present in fair weather? Stormy weather?

Taking It a Step Further: Take pictures of the same part of the sky at the same time of day for five days. Watch the local weather report each of those days, and record the weather forecast

Q. How do the clouds match up to the forecast? Can clouds be used to predict what the weather will be the next day?

A. They can to a certain extent. An increase in stratus clouds may mean rain is on the way. Very few or no clouds mean fair weather should be in place for awhile. If cumulus clouds are getting tall, thunderstorms may be forming in the near future.