Skiers and snowboarders have many words to describe the different types of snow on the hill – blower pow, mashed potatoes, boiler plate, breakable crust, hero snow, and crud (among others). But what’s actually happening with the snow in these different phases, and more importantly, how does it impact your day on the slopes?
I caught up with Ryan Gage, Head Groomer and Assistant Mountain Manager at Mt. Bachelor, to find out how ski areas manage snow and what it means for you as a snowboarder or skier. We chatted about the life cycle of a snow flake and how ski areas preserve their most precious asset, “white gold.”
Fresh Powder Vs. Packed Powder
Snow at a ski area either comes from the sky or from machines. Fresh, dry, natural powder, with the classic snowflake shape (called dendrites), is the best kind of snow to ski – the lighter the better. The density of natural snow has to do with the temperature and humidity, Gage said.
“Dendrites (traditional snowflake-looking crystals) tend to accumulate with more air between them because of their shape.” Gage elaborated, “Furthermore, dendrites tend to form in drier air masses where the humidity is lower.” This results in the characteristic powder snow that you see in resort photos in magazines and on Instagram.
“Oppositely, column crystals have smooth lines along their edges and can pack together more easily, allowing for less air between them. The result is denser snow,” Gage commented. Though snow that is more dense is not as fun to ski, it contributes to the base depth more effectively than does light powder snow. Mt. Bachelor uses a graphic to display the current characteristics of the snow surface and of any new snow, effectively communicating to snowboarders what the conditions will be like when they get to the mountain (seen in the image below).
Most ski areas in North America have a snowmaking system to augment what Mother Nature produces. The snow accumulates in piles near the snow guns, which means the grooming crew has to push the snow around to equalize the base depth. As well, machine made snow is not as light or fluffy as natural snow. “Man-made snow does not have as sophisticated of a crystalline structure as natural snow. It starts out much farther along the path towards the end of its life as snow,” Gage noted. So even fresh man-made snow isn’t as fun to ride as natural powder – but it does provide a surface to ski on and also adds to the base depths that ski areas need to sustain operations.
Time and Traffic are the Enemy
You’ve heard of the saying, “Change is inevitable”. The same goes for the snow under your feet. The snow surface on the run you just skied will not be the same the next time you’re on that trail again, even if it’s the very next run. “Snow crystals are in a constant and continuous state of transformation,” said Gage in describing how snow changes over time. “Every time a machine, skier or rider touches the snow, the crystal structure changes. And there are only so many times the crystal can change its structure before it reaches the end of its life as usable, workable snow.”
So how do ski areas keep their snow fresh, aside from praying to the snow gods for a refill every couple of days? Some ski areas mix new snow into the old snow, particularly in high traffic areas like lift ramps and base areas. Ski areas move snow from decks, parking lots, and even from the woods to freshen up the snow surface; this snow can be stored in shady, north-facing locations until it is needed. “Ideally, the old snow is where you want it, and the new snow can be brought in to top it off when and where it’s needed,” commented Gage about moving snow around Mt. Bachelor.
What has the biggest impact on changing the snow? “Rain,” said Gage. “Rain has a dramatic effect on crystalline structure; it ends the life of a snow crystal faster than anything else. Sunshine and/or melt-freeze cycles also accelerate crystal changes, but not as fast as rain.”
Management of the snow surface at your favorite ski area is a big deal, and it’s no accident that ski areas work so hard to keep the snow in the best shape possible. Next time you’re out on the hill, look around at all the trails that are open with snow on them, and give thanks to your snowmaking and grooming team!