The science of snowmaking

We all thank Ullr, the Norse god of snow, when he blesses our mountains with fresh, sparkly powder falling from the skies, but we owe most of our early season turns to the science of snowmaking. Snowmaking is what allows ski areas like Breckenridge Ski Resort to open before we get our first major snowfalls of the winter, but exactly how does it work?

It turns out that snowmaking is a bit more complicated than just turning a hose on and pointing it skyward. In fact, it takes just the right mix of temperature, humidity, water, and compressed air to coat our ski slopes with lovely white snow.

You might not be surprised to learn that air temperatures need to be low for blowing snow. In fact, even though 32º F is the freezing point of water, temperatures lower than 28° F are ideal for snowmaking. Equally important is the wet bulb temperature. The wet bulb temperature is a measurement that factors together both the outside air temperature and relative humidity levels. Relative humidity tells us how much moisture, or water vapor, is in the air. For snowmaking, dry conditions are best.  Why? Because water cools through evaporation. That’s why your skin feels cooler when your sweat evaporates. When sprayed from the snow guns, droplets of water vapor evaporate a little bit and become colder. When the humidity is high, the air is already saturated with moisture, and the droplets don’t cool as quickly. Dry air makes the water vapor cool much more rapidly, which means it’s easier for those droplets of liquid to become frozen crystals – snow!

Of course, Breck can’t make snow without the snow guns! You’ll often see snow guns with one or two hoses attached to them. These hoses supply the snow guns with plenty of water and compressed air. The compressed air has a few purposes: It breaks up the flow of water into tiny water droplets and blows those water droplets up into the air while also cooling them. Some snowmaking systems can turn thousands of gallons of water into snow each minute!

It takes a lot of energy to run the air compressors and to pump all that water uphill. Snowmaking is an energy intensive process, but Breckenridge Ski Resort is committed to adopting more efficient snowmaking practices. Recently, the resort installed 296 new snow guns which use one-third as much energy as older models to make the same amount of snow. There are also 8 new fully automated fan guns which churn out tons of snow onto the Freeway terrain park. Together, these improvements save about 1.2 million kilowatt hours of energy annually, which is enough to power 110 homes in the United States for an entire year.

Snowmaking helps our resort to provide the experience of a lifetime to everyone who comes to ski Breck’s awesome slopes, and through Epic Promise, we’re finding better and more efficient ways to do just that!

– Jess Hoover