cloud up

There seemed to be no wind, but the great country of white cloud up aloft had advanced, and a soft gloom filled the Glyn.

Or sometimes if you're lost and following the stars, it'll cloud up and you can't see them any more.

Weather fine this forenoon but began to cloud up towards night.

No more the tall masts cloud up, as the sky clouds, at the captain's word of command.

“This is my idea of living,” he proclaimed as he sent a blue cloud up toward the rather awful dome-light above the big table.