Sparks flew, and a cloud of smoke roiled in the air.

The clouds still roiled around him, but the lightning didn't come.

The low grey clouds roiled across the sky; it was probably only about eight degrees outside.

The moon hung motionless, while around it the clouds roiled.

In one of the new television commercials, dark clouds roil ominously across the screen.

The clouds roiled and struggled to free themselves of their confinement.

Dark, heavy clouds roiled above the gray mountains beyond the canyon.

Luminous clouds roiled in the sky, and lightning began to strike all around us.

With the night and the dark clouds roiling overhead, visibility was limited to a few score feet.

The air was cool, and the clouds roiled overhead.