1. Clouds Second Grade Science
By: Christy Gibson

2. Clouds
A cloud is composed of tiny water droplets (or ice crystals) that are suspended in the air.
If the droplets become large enough, they may be visible as a cloud or fog.
The process behind cloud formation is called condensation.
Clouds are referred to as either low, mid, or high-level clouds.
This classification depends on where they are in the troposphere.

3. Variations/Combinations of the three:
Types of Clouds
Three main types:
Stratus
Cirrus
Cumulus
Variations/Combinations of the three:
Nimbostratus
Altocumulus
Altostratus
Cirrostratus
Cirrocumulus
Cumulonimbus

4. Types of Clouds
Stratus clouds are grayish clouds that often cover the entire sky.
They look like fog that does not touch the ground.
People often confuse it for fog.
When a thick fog "lifts," or moves up, the result is a low stratus cloud.
Usually no precipitation falls from stratus clouds.

5. Stratus Clouds
Low lying Stratus
Fog

6. Types of Clouds
Nimbostratus clouds form a dark gray, "wet" looking cloudy layer.
This type of cloud is often associated with falling rain or snow that is falling continuously.
They often produce precipitation that is usually light to moderate.

7. Nimbostratus Clouds

8. Types of Clouds
Altocumulus clouds are middle level clouds that are made of water droplets.
They appear as gray, puffy masses, and sometimes roll out in parallel waves or bands.
If you see these clouds on a warm, humid summer morning it probably means thunderstorms may happen later in the afternoon.

9. Altocumulus Clouds

10. Types of Clouds
Altostratus clouds are gray or blue-gray middle level clouds.
These clouds usually fill up the entire sky.
In areas of the cloud that are thinner, the sun may be dimly visible as a round disk.
Altostratus clouds often form ahead of storms that will have precipitation that falls continuously.

11. Altostratus Clouds

12. Types of Clouds
Cirrus clouds are thin, wispy clouds that get blown by high winds into long streamers.
They are considered "high clouds" and form above 20,000 feet.
Cirrus clouds usually move across the sky from west to east.
When you see them, it normally means fair to pleasant weather.

13. Cirrus Clouds

14. Types of Clouds Cirrostratus clouds are thin and sheet like clouds.
They often cover the entire sky.
They are so thin that you can see the sun and moon through them.

15. Cirrostratus Clouds

16. Types of Clouds
Cirrocumulus clouds look like small, rounded white puffs or blobs.
The small waves, or ripples in the cirrocumulus sometimes resemble the scales of a fish.
If the sky is filled with cirrocumulus clouds it is sometimes referred to as a "mackerel sky."

17. Cirrocumulus clouds

18. Types of Clouds Cumulus clouds are puffy clouds.
They sometimes look like pieces of floating cotton.
The bottom of each cloud is often flat.
The bottom may be only 330 feet above the ground.
The top of the cloud has rounded or billowing towers.
They grow upward.
They can turn into a giant cumulonimbus.
A giant cumulonimbus is a thunderstorm cloud.
These types of cumulonimbus clouds are typically grayish black.
Lightning, thunder, and even violent tornadoes are associated with the cumulonimbus.

19. Cumulus clouds
Cumulonimbus

20. Questions?