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I hope this finds Everyone keeping well and enjoying the Holiday season.
I spent the day touring in the Oboe Basin area of the Fitzsimmons Range. Here are some of the things I noted:
It has been great to finally receive some new snowfall. The new snow that has fallen seems to amount to 30cm or more, and much deeper in places that have received wind-loading. I did not observe any alpine terrain today, so my observations are from treeline elevations and below. Exposed (open) treeline terrain has recently received some wind-effect and the surface snow is a little more slab-like, but skiable. There was evidence today of both natural and skier-triggered soft slabs that were in the size range classification of 1 to 2. Most of these results were in that open terrain around treeline and in 'alpine-like' features around treeline elevations. Other terrain characetristics that were favoring triggering today were lee (northern aspects), steeper, rocky, slopes immediately below ridgecrests, and on convex (bulging) terrain that was wind-loaded.
I felt numerous 'whumpfs' in low-angle, open, and below-treeline terrain that was east-facing. I stopped and had a dig for the suspicious layer and found the 'surface-hoar' that was buried around the middle of this month. These crystals were still obvious and were between 5mm and 9mm in size, and resting just below a very thin and decomposing crust. These crystals 'seemed' to disappear with elevation gain into more open terrain that was more influenced by wind, sun, and those warmer temperatures of early-mid December. As below-treeline elevations give way to treeline elevations, and again in open north-facing terrain, a layer of old facets can still be found down 48cm from the surface. The snow above any of these weak layers, at these elevations and in these spots that were less affected by the winds of late, is soft. As we receive new loading and if the temperatures warm, then I suspect these layers will become more reactive, for a while.
There is currently an honest coastal-storm settling into the mountains here and it's snowing hard, and that's being accompanied by strong winds. Expect the avalanche danger to spike during, and immediately after, this storm. The size of the slabs that can be triggered will increase during this cycle.
It appears that Winter has returned.....
Best wishes and safe travels,
Dale Marcoux
ACMG Ski Guide
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