“It’s going to be 32 degrees tonight. Technically, that’s freezing. Can you make snow?”
It’s a little more involved than that, as snowmakers have some additional things to consider. Sorry, Sam Champion.
Allow me to introduce you to the term, “wet bulb.” In the simplest of terms, wet bulb is the true temperature after factoring in humidity. (Standard thermometers measure the “dry bulb.”)
“Whoa. Why does humidity matter? I thought it was only a summertime thing.”
Water cools itself off by evaporating. When there’s a high level of humidity (a lot of water already in the atmosphere), water can’t evaporate as much. When humidity levels are low, water can cool more quickly.
So, a low wet bulb (temp & humidity) equals better snow production.
“Great. So toss me some numbers. What’s the ideal snowmaking situation?”
There’s no definitive cutoff temperature that says we can or can’t blow snow. Ideal temps usually range from the teens to mid 20’s, but again… humidity is the deciding factor. (Sometimes, if the humidity is super low, we can make snow when the temp is above freezing. Who’da thunk it.)
To give you an idea... if the temperature is lingering around 30*F, you’d need a humidity level of less than 30% to fire up the guns. If the temp is lower than 20*F, you could probably make snow rather easily, even if the humidity level was at 100%.
Welp! Now you know some of the thinking process behind snowmaking. Give your neighborhood snowmakers a hug next time you see them. They’re awesome, and they deserve it.
-Halley
