It dawned with cool air this morning, but the water in the Lake was still warm. Then, cold drainage winds from the mountains rushed down and out over the Lake and steam fog formed.
But, one other feature was necessary for the formation of steam devils: a strong wind shear. Another way of saying this is that what was now needed was a strong change in the strength of wind with height. There was a wind shear, but only a moderate one. Nevertheless, a few steam devils formed.
Mind you, the sun quickly warmed the mountain side stopping the drainage wind and killing both the steam fog and the steam devils. It was fun while it lasted.
A mediocre steam devil towered over the steam fog on the Lake.
