Chapter 12 Section 5 How do clouds form? Objectives: Describe how clouds form. Identify kinds of clouds.

Key Terms cirrus cloud: light, feathery cloud cumulus cloud: big, puffy cloud stratus cloud: sheetlike cloud that forms layers across the sky

Cloud Formation Clouds form from condensation in the atmosphere. Water droplets and ice form around dust and other particles in the air. Many billions of tiny water droplets and ice crystals form clouds. A cloud’s shape is determined by how it is formed.

NAME: What process forms clouds?

Kinds of Clouds Cirrus clouds made up of ice crystals sometimes form at heights above 10,000 m Cumulus clouds form from rising currents or warm air that build to great heights the base is usually flat Stratus clouds form layer upon layer usually at low altitudes

2. LIST: What are the three basic kinds of clouds?

Fog Fog: a cloud that forms near the ground Forms from condensation The ground cools quickly at night It cools the layer of air that lies above it The air may be cooled to the dew point If it is, the water vapor condenses and forms fog

3. DESCRIBE: What is fog?

Cumulonimbus Clouds Cumulonimbus clouds = often associated with thunderstorms As the clouds rise, their tops become flattened against the tropopause This large, flat top resembles a blacksmith’s anvil. An anvil is a good indication that a thunderstorm is coming.

4. COMPARE: How is a cumulonimbus cloud like a cumulus cloud?

12-5 Classwork What are clouds made of? What are light, feathery clouds called? What are sheetlike, layered clouds called? What kinds of clouds are large and puffy?