It Actually Looks Like Winter

I got up this morning to a light dusting of snow on the grass, and a mix of snowflakes and raindrops gently falling through the air...it now looks like it is all rain. It is not that the air was particularly cold that caused the snow, but that the air has been extremely dry. The last few days have been beautiful with clear blue skies. The reason that we did not have fog and low clouds is due to the very low humidity. As the weather changed, and precipitation begins to fall overnight, the rain falling through the dry air will evaporate. The process of evaporation, a change from liquid water to water vapor, requires heat to be absorbed by the water molecules to occur. That heat comes out of the air so the temperature of the air drops. As it drops the snowflakes falling from higher up in the clouds, a few 1000 feet, no longer melt on the way down since the air below has cooled due to evaporation. The end result is that the snow level quickly drops and those of us that live in the higher ground around town get a little taste of winter this morning. It won't last...any hint of the snow will be gone well before noon.