CRCT QuestionWhich type of cloud indicates fair

weather?a. Stratusb. Cumulus c. Cirrus d. Stratus nimbus

Think, Pair, ShareWhat do you know about

clouds?!?!

Water in the Air Water gets into the atmosphere through

evaporation.Called humidityCauses cloudsChanges density of the airDew Point – temperature at which

condensation occurs. Depends on the humidity and air temperature.

Clouds form at whatever elevation dew point is reached

Rain shadow – caused when water vapor hits mountains, gets pushed upward, cools off, condenses, and drops it water vapor load – all on the windward side of the mountain.

Is a measure of how much water vapor is in the air.

It is measured in a percent using a psychrometer.

More humidity means more clouds and more likely chance of precipitation.

This forms clouds!

http://www.wildlandschool.net

Clouds form when the water vapor reaches the dew point.

Remember that as you go up in the troposphere, the temperature decreases.

Dew point

This is the reason clouds look to be about the same height in the sky and

flat on the bottom. They are!

Dew point temperature is reached.

Types of CloudsCumulus – cotton balls – indicates fair weatherStratus – flat layers – often has precipitationCirrus – high, thin clouds – usually means change in weatherFog – cloud on the ground

Let’s Take a Closer Look!

Cirrus – highest type of cloud. Due to elevation, made of ice crystals. They indicate that a change in the weather is coming.

Cumulus – round, puffy cloudsIndicate fair weather

They can build up to form storm clouds that contain hail, lightning, and tornadoes.

Cumulonimbus clouds often produce bad weather (lightning and hail) Nimbus/nimbo means rain. Notice that it is getting flat on the top. That means the top of the cloud has reached the top of the troposphere and cannot go any higher.

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Cumulonimbus

Stratus – flat layer of clouds. Often have rain.

Nimbostratus clouds often produce rain for many hours. Like stratus clouds, they cover the sky. The only difference is that these are

producing rain or snow.

Other cloud types

If the dew point temperature is the same as the air temperature on the ground, fog

forms! The cloud actually forms on the ground.

Precipitation –cloud droplets get too heavy to stay in the cloud

Kinds of precipitationRainSleetHailSnow

Measured with a rain gauge or ruler

What is the difference between

rain and mist?!

The term rain is restricted to drops of water that fall from a cloud and have a diameter of at least 0.5 millimeter.

Drizzle and mist have smaller droplets.

The most common form of precipitation is rain.

As water vapor collects into larger

and larger droplets, gravity

will cause them to fall to the ground as rain, sleet, hail,

or snow.

Drizzle droplet

Mist droplet

Cloud droplet