In places where wind and sun and high-moisture content can wreak havoc, it’s less about the powder sometimes and more about the view and the atmospheric lighting.
We are all likely particular about snow. Although we are lucky to be skiing or riding anything at all, powder snow often rules them all. But when it comes to powder, how dense is too dense?
Our skis or snowboards are extensions of our sense of touch. As such, we can tell many things about the snow as we tilt toward the fall line—imagining our first and second or third turns. Before that, you’ve skinned to the top and poked a pole to probe snow depth. Feeling for any vagaries about the snow you’re about to ride.
Density has been on my mind. First, in a recent article, I was reminded of the nuanced work of Vermont’s Wilson Bentley way back when. The piece claims Bentley was a “snowflake obsessive.” Bentley’s inquiries into the micro was when “snowflake” had less harsh connotations: snowflakes were simpler, I suppose, back then. Just frozen crystalline forms of water that piled up and was pretty damn sweet to slide on.
Density is also on my mind after this weekend. I learned, yet again, that there’s sometimes some dissonance between how we expect conditions to be and how they pan out. The first indication was the drizzle as I walked my pooch Riley on Sunday morning. I strolled along, mist forming on my glasses at Roughly 3500’ in elevation. Low enough for rain, high enough to dampen my optimism for cold snow in the hills. In short, the conditions did not align.
As we skinned up the first incline a few hours later, the humidity inside my hardshell matched outside atmospheric conditions. Clouds hung low. The snow, while not classically Cascade Cement, was more mashed potatoes than light and airy potato flakes. I was accompanied on this tour by two friends from the Wasatch, Barb and Pete, who were here for the long weekend. Although I don’t control the weather, I felt a meteorologist’s guilt after a broken promise of 6-12” of fluff. “Dude, the snow is great,” I heard from Barb and Pete. They are lemonade makers.
They are also used to 2,000 to 3,000-foot runs, and although it’s hyperbole—sometimes there’s truth in hyperbole—accustomed to the greatest snow on earth.
Locally, we often have heavier, denser snow. I know riding conditions are fleeting. There is always the promise of tomorrow. Yet, especially wet and heavy conditions leave a lasting impression. Rather than get bogged down in the lemons and their bitterness, let’s pivot to some science by examining a table of metrics and terms relating to snow density.
Powder, you know when you ski it.
The table is from a course curriculum at the University of British Columbia titled “Weather for Sailing, Flying & Snow Sports.” Let’s focus on snow density between 100-200 (kg m-3), the so-called powder snow. A range of 100 kg m-3 is a mighty big range considering the quality of powder snow. From the greatest snow on earth to “yeah, that might be powder snow,” it all, optimistically, can be powder. (Remember, we’re channeling Barb and Pete to make lemonade.)
The same course curriculum claims this:
“Newly-fallen snow that’s about 7% total water content or less would be considered light, low-density snow, and the average is about 8-11%. Snow that is 11% or more is considered heavy snow. If you look at the average snow density across North America (in and out of the mountains), it’s about 8%. Remember that this all refers to newly-fallen snow, before it has settled (or been compacted like in a ski resort).
“The optimum snow density for powder skiing is actually not the lightest snow possible, but rather snow that’s around 8% total water content. This medium-density snow is still easy to ski and light to push around/through, but has enough “body” to provide flotation. In very low-density snow (~5%) skis/boards have more of a tendency to push through the snow instead of floating on top of it….”
Peeking through fingers down at my skis. Although this snow trends toward the 11% water-content side of the powder-god benchmarks, the skis make it feel more like 10%. For that I am grateful.
The only science conducted during Sunday’s ski was the kind quantifying grin size. We did find a stash of snow that skied somewhat light, eventually, but I think that had more to do with the increased slope angle and the resulting ability to plane a bit more. Go figure—lots of tip and tail rocker, big-time ski surface area, can be smile inducing in less optimal powder. And so, ample-sized grins were had. Yet, had there been a device to measure snow density and/or % water content, we would have been on snow at the margins of 11.99%. Of that, I am certain.
There are days when I’m looking for some cosmic rounding error. For engineers I suppose it’s a pretty massive rounding error in the grand scheme of things. I hoping for something in the order of -3.5%. That margin might bring 11% water-content snow (denoting heavy snow, according to our experts in academia) down to a mere 7.5% water content. That may be too much to ask.
