"I really don't know clouds at all," folksinger Joni Mitchell once noted in her lyrics. Which is too bad, because we would have been glad to tell her all about clouds. While it's up to you to decide which ones look like ice cream castles in the air, here are the most common cloud types found in the atmosphere, according to the Center for Science Education.
Altocumulus are mid-level grayish-white clouds, which have one darker and one lighter part. If you see them on a warm, humid morning, you might have a thunderstorm in the afternoon.
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