1. Aim: How do clouds form? Notepack 37
Do Now: Explain why it rains more in the Summer time than in the Winter.

2. Cloud Formation Air cools for 3 reasons:
As air rises it usually cools
As air more over cooler surfaces
When the amount of sunlight becomes less
As the temperature of the air cools, its ability to hold water vapor becomes less.
Some of the water vapor condense (turn back to liquid water). The Dewpoint!
If enough condensation occurs, than a cloud may appear.
If the cloud is formed near the ground it is called fog.

3. Types of Clouds Cloud can be categorized into 3 groups:
High-level Clouds
Medium-level Clouds
low-level clouds

4. Types of High-level Clouds
There are three types of high-level clouds:
Cirrus
Cirrostratus
Cirrocumulus

5. Cirrus Cirrus clouds are above 18,000 feet. They are long and wispy.
Usually mean good weather.
These clouds look like feathers.

6. Cirrostratus
Thin and sheet like.
Brings bad weather.

7. Cirrocumulus Rows of long white puffs. Look like fish scales.
In tropical regions.

8. Types of Medium-Level Clouds
There are two types of medium-level clouds:
Altostratus
Altocumulus
Medium-level clouds are between 6,500 – 18,000 feet in the air.

9. Altostratus Are colored gray or blue-gray. Covers the whole sky.
Appear before long periods of rain or snow.
Clouds of a cloudy day.

10. Altocumulus
Are puffy and gray.
Usually bring thunderstorms.

11. Types of Low-Level clouds
There are three types of low-level clouds:
Stratus
Stratocumulus
Nimbostratus
Low-level clouds only go up to 6,500 feet in the air.

12. Stratus Clouds Stratus clouds cover the whole sky.
Looks like fog in the sky.
Brings light rain.

13. Stratocumulus Are low, puffy, and gray. Form in rows.
Can turn into a Nimbostratus cloud.

14. Nimbostratus Are dark gray. Associated with rain and/or snow.
Produce precipitation light to moderate.

15. Clouds that grow vertical
There are two types of clouds that grow vertical:
Cumulus
Cumulonimbus
Vertical means: (in this case) to grow upward.

16. Cumulus Clouds Cumulus clouds are big, white, and puffy.
Like cotton balls
They grow upward.

17. Cumulonimbus
Are anvil shaped. Winds blow the top of the cloud to make it flat.
Associated with severe weather.
The tip of the cloud points in the direction it is moving.

18. Precipitation
Precipitation refers to any form of water falling from the sky.
Precipitation can be:
Rain
Snow
Sleet
Hail
Precipitation occurs when the condensation inside a cloud is too heavy for the air to hold

19. Precipitation
All precipitation start out as rain but if they stay as rain or into something else depends on what happens to it on the way down.
If the temperature in the air is above 0o C (Freezing) that the precipitation stays as rain.
If the temperature in the air is exactly 0o C the precipitation change to sleet (ice and rain).
If the temperature in the air is below 0o C that the precipitation turn to snow.
If the rain drop is caught in an updraft (wind moving up), than it will turn to ice (hail).
The size of the hail depends how many times the ice is caught is an updraft.

20. Precipitation