Weather Wise Kids: Why does it rain instead of snow when it’s below freezing?

Winter weather forecasting can be tricky, but let’s break it down.

There are four main types of precipitation: rain, freezing rain, sleet and snow.

Which type your town gets depends on the temperature…

Did you know most precipitation actually starts as snow? This is because the air high up in the atmosphere is below freezing.

In the simplest terms when the temperature at the ground is less than 32 degrees, the snow will stay snow… And when the temperature is above 32 degrees, the snow will begin to melt and fall as rain.

But there is so much more….

Regular rain turns into freezing rain when the earth’s surface has cooled down to temperatures at or below freezing.

Since the rain is not freezing until it reaches the surface, it still falls like regular rain…and therefore looks and feels the same as rain until it freezes on the ground.

Snow forms when the temperature near the clouds is low enough to freeze. If the atmosphere stays below freezing between the clouds and the surface, then snow will reach the ground. This is why there can be snowy periods even when the surface temperature is above freezing.

But it doesn’t stop there. Sleet forms due to three different layers. Think of it as an atmospheric sandwich…yum!  The top layer is below freezing the middle layer is above freezing, and the bottom layer is below freezing. The precipitation begins as snow in the frozen layers, melts to rain in the middle layer, and refreezes in the bottom layer, before finally falling to the ground an frozen ice pellets or sleet.

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