Winter precipitation types

Do you know the difference?
Posted at 5:40 PM, Dec 12, 2019

The time for winter weather is upon us. Here in Kentucky more times than not all types of wintry precipitation are on the table ... from rain to snow, freezing rain, or sleet. Do you know the difference? Read on to learn more.

The type of precipitation falling through the atmosphere can change from cloud level to the ground. All precipitation starts the journey down to the ground as an ice crystal. The type of precipitation can go through a transformation or two on its way down depending on the temperature. That's how we get the different types of wintry precipitation.

Let's start with rain. Again, at cloud level the precipitation is frozen, in the form of snow. The snow melts to rain as it travels through a deep layer of warm air that extends all the way to the surface.

What goes on aloft is similar for rain and freezing rain. Snow is released from a cloud and melts to rain as it encounters a warm layer. With freezing rain there is the complicating factor of a shallow layer of sub-freezing temperatures close to the ground or cold surfaces. The "rain" will freeze on contact with these cold surfaces, creating icy conditions on roads, bridges, and sidewalks.

Sleet begins with melting ice crystals above the surface. Re-freezing into ice pellets occurs as the precipitation falls through a larger cold layer above the surface. A bing on your windows is a sure sign that sleet is falling.

Finally there's snow. Precipitation will remain frozen when freezing temperatures extend from the cloud base to the ground.