Check out the timelapse video! You can see this shot in motion around 42 seconds in. http://www.youtube.com/watch?v=bS8Q669T8AQ
I love seeing the lake steaming in the morning. I see it fairly ofter in early and late winter, usually in the morning.
From Wiki... Sea smoke, also called steam fog or evaporation fog, is the most localized form (of fog) and is created by cold air passing over warmer water or moist land.