Mar 3, 2014 9:46 AM by Stephen Bowers
Odds are, after even light snow you've seen this:
The smoky roads as the snow melts. Why do the roads become smokey after our snow in Colorado? Many of us have seen the smokiness that forms over warm rivers or lakes when cold air moves over them. That's a steam fog, or a "mixing fog" that forms. It's the same basic thing happening as our snow melts. The humidty is low, so evaporation occurs fairly quickly of the water left behind from melting snow. The water evaporating adds water vapor to the very cold air and spikes the humidity up to 100% near the ground, causing that fog to form.
That leads us to another question: why doesn't this happen in other areas. Most other areas, like in Virginia, Pennsylvania, New York and even Washington and Oregon have higher humidity. In other words, a lot of water (in the form of vapor) is already present in the air, so the water from melted snow does not evaporate as readily to form that fog.