Why Is The Sky Blue? is a regular series where experts who normally explain complicated scientific phenomena at the PhD level try to explain those same concepts to your kids. Since you never know where snow is going to fall these days (thanks climate change!), we checked in with the University of Utah’s atmospheric sciences professor Jim Steenburgh — a guy proud to refer to himself as a “weather weenie” — to better understand snow from the perspective of someone who’s only seen it a few times, or never seen it at all (meaning, your kid. Steenburgh basically lives in the stuff).
Your Kid’s Questions
So, is snow just frozen rain?
Nope. Rain is a simple drop water, but snow forms when little bits of clouds go from being wet air to ice (and skip the whole “drop of water” phase, but you can explain sublimation to them another time). Rain forms in all sorts of clouds, but snow only forms in really cold ones, usually around 20 degrees in the top portion of the cloud. That’s where a lot of the bouncing around happens that turns the air to ice; how the ice bounces around determines if the snow falls as a tiny little pebble of ice or as one of those crazy looking snowflakes.
No one can say for sure that no two snowflakes are alike, because they keep melting before anyone can check.
Oh yeah — no 2 of those are alike, right?
Well … about that. All snowflakes are alike in that they have 6 sides, because their skeletons are 6-sided (by “skeleton” you mean “molecular level,” in the event that you’re already raising a chemist who understands those things). As the flake drops through the cloud, more wet air freezes around each side, and since no 2 snowflakes take the same route to the ground, they all form a little differently. But no one can say for sure that no two are ever alike because they keep melting before anyone can check.
Your kid should remember Thundersnow when they take up an instrument in high school, because it’s a totally awesome band name.It’s not white, exactly, it just looks that way.
Why is snow white?
Since snow is really just fancy little bits of ice, it reflects light the same way a frozen pond might. But a frozen pond is one big reflecting surface; a snowflake or snow pebble has roughly a gazillion surfaces, all pointed every which way. Each surface reflects the color of whatever it’s pointed at, but when there’s that many different colors being reflected all at once, all you can see is white. It’s like when it gets so loud in the car that you can’t hear your mother, except its your eyes that get overwhelmed instead of your ears.
How come it doesn’t thunder and lightning when it snows?
Oh, but it does! It’s called “thundersnow,” and it’s pretty rare, but is sometimes seen (or heard) in snowstorms that develop over big bodies of water like the Great Lakes. Thunder and lightning form in really tall clouds that have lots of air moving up and down in them, but most snowstorms form in shorter clouds. Bodies of water can disrupt those short clouds and create conditions that produce thunder and lightning. Even if you never see it, you should remember thundersnow when you take up an instrument in high school, because it is a totally awesome band name.
Those recent snowstorms in western New York were crazy, right?
They were impressive — one spot outside Buffalo received 65 inches in 24 hours — but they didn’t set any records. The record in the U.S. is held by Silver Lake, Colorado, where 75.8 inches fell between April 14 and 15, 1921. Alaska disputes this record, as observers claim 78 inches fell in one day at Mile 47 Camp on February 7, 1963, but the National Climate Data Center still lists Silver Lake as the winner. Meanwhile, the record holder for one year is 1,140 inches (that’s 95 feet), which fell on Mt. Baker ski area in Washington the winter of 1998-99. Incidentally, Mt. Baker is among the more reliable places to plan a ski vacation if tons and tons of snow is your first priority. Just remember, it’s very easy to lose track of your kids in places that measure single storm totals in feet, not inches.