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The science behind snow: A lesson on how snow forms

The surprising reason we use salt when it snows
Posted at 12:34 PM, Nov 27, 2017
and last updated 2017-11-27 19:41:09-05

OVERLAND PARK, Kan. -- When I asked my son Skyler what he would like to see me do for The Wonders of Winter special, he said "What about everything about snow?"

I thought it was a good idea so I went to Skyler's school, the Hyman Brand Hebrew Academy, and talked about how snow forms.

Here's what I taught them:

Snow forms from dust and smoke particles in the clouds when the temperature up there is at or below 32°. Ice crystals then combine on those dust and smoke particles, also known as aerosols. When enough ice crystals have come together, they form a snowflake. Once the snowflake is heavy enough, it falls to the ground.

It starts snowing as long as the temperature on the surface is cold enough -- otherwise the flakes could melt into rain drops in the warmer conditions.

In the science class, I did an experiment and made fake snow. It's not how snow is actually made, but the kids and adults loved it.

This experiment can be as easy as adding water to some instant snow powder if you want to try it at home.

I wasn't the only one giving a lesson that day,

When it snows, the first thing road crews do is put salt on the road. But why? I turned to science teacher Cody Welton to explain.

Mr. Welton explained that salt does not actually melt the snow. Instead, the salt lowers the freezing point of water, so ice and snow turn to liquid when they come into contact with the salt. In addition, any existing water on already surfaces will not freeze once salt is added.