Fog In The Park

I was on the way back from recycling when I drove past this park bench standing out from the background because of the fog above the snow.  I started thinking about this shot, but didn't slow down.  When I got to the next corner, I finally figured out that this was a photograph.  So I turned right and then right 3 more times, and this time parked the car and grabbed my camera.  Only one problem.  A faint wind had come up and blown the fog away!  Oh no.  But I stood there waiting, and the wind died and so very gradually more fog formed over the snow.  Do you know why?  When the air is saturated with water, like when it is raining, if you cool it, it condenses and forms fog.  Same thing happens with clouds.  Warm, moist air is heated by the ground and then it rises because it is warm.  As it rises, it cools because the temperature decreases as altitude increases.  When the moist air cools enough, then it condenses, and clouds form.  How cool is that!