All cloud types
Cloud Name
Altostratus
A grey-blue sheet that dims the sun and often arrives before widespread rain.
What it looks like
Altostratus covers much of the sky. The sun may look like a pale disk behind the cloud.
Simple meaning
This often means a weather system is approaching and rain may arrive later.
For boating
Good time to review the forecast, plan shelter, and check if wind will rise with the front.
How to recognize Altostratus
- Grey-blue sky
- Weak sun outline
- Wide smooth sheet
- Cloud base slowly lowering