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Stratus clouds (thanks to NASA)

Stratus clouds (thanks to NASA)

What are stratus clouds?

If you see stratus clouds, that’s the time to get inside and stay there. Stratus clouds mean rain if it is warm and snow if it is cold. They look like a huge gray blanket that hangs low in the sky. Sometimes stratus clouds are on the ground or very near the ground, and then we call them fog.

Strato-nimbus clouds
Strato-cumulus clouds
Other kinds of clouds
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How do stratus clouds get started?

Usually stratus clouds and fog form when it has been cold out and then warmer, wet air blows in. As the warm air flows over the cold ground or over the cold air near the ground, the water vapor in the warm air condenses into drops of water that make a cloud. How thick the cloud is depends on how wet the air is and how big the difference in temperature between the cold air and the warm air is.

Hot air rises
More about temperature

Two types of clouds mixed together

Strato-cumulus cloud (from NASA)

Strato-cumulus cloud (from NASA)

Clouds can be a mixture of two types at the same time, so you can also get strato-cumulus clouds or strato-nimbus clouds. A strato-nimbus cloud is a stratus cloud that has rain falling out of it. A strato-cumulus cloud is a stratus cloud that covers the whole sky, but is still puffy like a cumulus cloud.

Learn by doing: clouds
More about clouds

Bibliography and further reading about stratus clouds:


Learn by Doing – Clouds
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