Don't Lose the Ball in the Fog

I was mildly amused to see Wrigley Field and Cellular Whatever field where the White Sox play engulfed in fog. They did not call the game, as far as I know, and I don't know if the conditions were bad enough to cause them to lose track of the ball in the outfield, but it was an interesting sight to see on television. I didn't know that this was "commonplace" or if it is something that happens once or twice a year.

It's Chicago. Who cares?