There were enough now to form a dark cloud, as if the outside storm had found a way in.

These gases form a cloud around the core of the star.

It the air, water vapor can form clouds which block light.

A jet of hair shot out and formed a cloud around the pot.

These are ways air can cool enough to form clouds:

Wings form clouds above the watch to represent "eternal time".

Her breath formed a faint white cloud as she spoke.

They formed a cloud above us and rushed in circles.

Steam rose from the surface of the water, forming clouds around their heads.

The men's rapid breath now formed clouds before their faces as they spoke.