CloudsClouds

• What are What are clouds?clouds? • How are they How are they

formed?formed?

•What do they What do they indicate about the indicate about the weather?weather?

What Causes Clouds?What Causes Clouds? Building on What We Know Building on What We Know

•Sun heats Sun heats surfaces.surfaces.

•Surfaces heat Surfaces heat the airthe air..

•Warm air Warm air rises.rises.

What Causes What Causes Clouds?Clouds?Step 1: Step 1:

EvaporationEvaporation•Liquid water Liquid water eevaporvaporates into ates into

water water vapor.vapor.

•Liquid changes Liquid changes to to gas.gas.

What Causes Clouds?What Causes Clouds?EvaporationEvaporation

• Water vaporWater vapor rises with rises with warm airwarm air

•Liquid waterLiquid water eevaporvaporates, ates, becoming vapor, or gasbecoming vapor, or gas

•Water vapor Water vapor fits in between fits in between air moleculesair molecules

•Notice warm air holds Notice warm air holds more more water vapor water vapor than than cold air.cold air.

What Causes Clouds?What Causes Clouds?Step 2: CondensationStep 2: Condensation

• Water vaporWater vapor cools along cools along with the air as it gets farther with the air as it gets farther from Earth’s surfaces.from Earth’s surfaces.

•DDroplets attach to dust particles.

•Clouds Clouds formform.

•Vapor condenses Vapor condenses into tiny drops of into tiny drops of liquid water.liquid water.

What Causes Clouds to What Causes Clouds to Form?Form?

A Summary:A Summary:• Sun’s energy heats water.Sun’s energy heats water.

• Water evaporates into water vapor.Water evaporates into water vapor.

• Vapor rises with warm air.Vapor rises with warm air.

• Vapor cools.Vapor cools.

• Vapor condenses into water droplets .Vapor condenses into water droplets .

• Clouds form.Clouds form.

What Are What Are the Three Main Types the Three Main Types

of Clouds?of Clouds?

Cumulus Clouds

Puffy

Flat bottoms

Formed from water droplets

Indicate fair weather

Cumulus Clouds

Cirrus Clouds

High in the sky Formed from ice

crystals Shaped like thin

threads or feathers Indicate warm air

and moisture coming

Mares’ tails

Stratus Clouds

Low in the sky

Formed from water droplets

Cover the sky like a blanket

Indicate rain or snow

Stratus Clouds

Other Types of Clouds Mixed together Cirro+cumulus High up Hard to see Small, fleecy like

sheep Mouton or

mackerel sky

Cirrocumulus

Cirrostratus High up

Cover sky in thin, milky-white sheets

Form halo

Bed-sheet clouds

Cumulonimbus

Name the Three Main Types of Clouds

Cumulus

Stratus

Cirrus

Thanks to…. www.googleimages.com Annie Lenox “Why” Mrs. McColgan’s photos