Jan 31, 2025 Conditions Report with Mitch Sulkers

Sudden Changes–What Now?

After 22 days with no snow, and the majority of those with sunshine, we have been left with a variety of older snow surfaces as a foundation for our current stormy weather!  On polar aspects, there has been a lot of near surface facetting, creating weaker layers either right on top of the snowpack, or where winds from the north were strong, just under a less than 10cm thick wind-pressed slab. On solar aspects, there were patches of sastrugi, wind sculpted waves, and on steeper slopes, a melt-freeze crust courtesy of a late January sun and a three-day strong temperature inversion in the alpine, with temperatures as high as 6C at 1900m in the Whistler area.

And then suddenly, we have substantial amounts of new snow falling on those surfaces, none of which are likely to promote strong bonding.

On January 31st, we found 34cm of fresh snow in the Callaghan at lower elevations, with totals increasing as elevation was gained. Mid-day, temperatures rose up a little, creating a slightly upside-down (heaviest snow on top) snowpack below treeline. A similar condition was created at treeline by strong winds moving the fresh snow. This form of layering, with stiffer/denser snow over lighter snow, creates a stability problem. The old layers from the 22 day drought as a foundation increased that problem.

On the evening of the 31st and early hours of February 1st, a similar amount of snow arrived, but with cooler temperatures. The drop in temperatures also helped to correct the upside-down snow problem below treeline, but as winds also rose during the evening, the slab problem at treeline and alpine was compounded.

On Saturday, February 1st, observations were conducted in the Oboe Summit/Melody Creek/Cowboy Ridge area. Occasional sunny breaks allowed for good visibility in the alpine. The best riding and stability was found below treeline, where the snow, although easily displaced, had not formed a cohesive slab. In steeper areas below treeline, the cold snow sluffed with turns and did not accumulate any size.

At treeline and alpine, however, the NE winds, shifting to SE winds, had created soft to hard slabs from five to fifty-five centimeters thick that were much more easily triggered in tests. Compounding this was the fact that much cooler temperatures were creating a temperature gradient down an average of about 25cm from surfaces that was favouring facetting processes again, which will create weaker crystals under the surface layers.

Also noticeable were cornice tab growths, with the most growth in NW aspects…

We chose to ride alpine slopes of less than 30 degrees that were protected from the SE winds, treeline slopes protected by tree bands, and below treeline slopes up to 35 degrees. All skied very well, although a light touch was best, as the old harder surfaces and old tracks below can still be felt on steeper slopes. Skiing under tree cover was not pleasant, as the forest canopy had collected much of the fresh snow for the moment.

As temperatures are forecast to drop into the -20’s at treeline early this week, it will be important to respect this snowpack. Even a small involvement could result in serious consequences, especially if there is an injury at temperatures like those forecast. Take the time to understand this new surface snowpack as you venture out, and avoid big slopes and convexities until the snow has a chance to really settle…there will be good skiing and riding, but it will be very important to keep observing as the days progress.