BALTIMORE — Precipitation comes in many different forms. It all depends on the temperature! Not just here at the surface but high up in the air as well.
Wednesday brought rain to some, snow to others, and even something in between that looked like ice pellets. In the image above you can see four different precip types. Each bar represents an air mass that goes up into the sky. Red is above 32° and blue is below 32°. Almost all precip starts as snow, but because it is warmer near the ground, the temperature generally rises as that flake falls. That means to get rain a snowflake melts and then never gets back below freezing. To see snow, that flake never melts. Those are the obvious ones. When we get a wintry mix the lines can blur. In the case of Wednesday we were just warm enough at the surface to see that snow start to melt and create little ice pellets.
