Observation: Public
Observation Details
Name:
Enji CooperObservation Date:
December 21, 2021Submitted:
December 21, 2021Zone or Region:
Stevens PassActivity:
XC Skiing/SnowshoeingLocation:
Skyline Lake/Heather RidgeTriggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
YesAvalanche Type:
Wet LooseSize:
Size 1: Relatively harmless to peopleElevation:
Aspect:
SComments:
Very limited pinwheels and rollerballs from digging out the col.Signs of Unstable Snow
Observations
Left for snowshoe around 11:00 from Stevens Pass Lot G; temperatures were in the mid 20s and mostly clear until 13:00, but warmed up and became more obscured as a light storm system (drizzle) came in and reduced visibility considerably along the ridge line—1 mile tops except the bowl, which was around 500’ or so of visibility.
Much of the snow acted like wet loose/storm snow when I went off the road. More so when I broke trail. Snowshoe penetration with tails was about 4”-8”, with exception of areas where I found especially weak deep powder/storm snow between the trees (I accidentally partly fell into a tree well about 2’-3’).
Given the complexity of the snowpack I observed, I approached with some degree of care by picking low angle slopes until I reached the last 200’ before the first col near Heather Ridge, but not a whole lot. Doing some digging, I found discovered that the snowpack consisted of 3” storm snow on top of 2 different 1’ deep layers separated by stout rain crust. I exercised some caution clearing the col by grooming the snow, i.e., digging with my ice axe and brushing off the top layer with my trekking poles. I broke down the individual layers column by column, building a bench by compressing the snow with my snowshoes to mitigate getting pushed downhill and buried by the storm snow or lower layers of wet loose debris. My grooming resulted in some large pinwheels and rollerballs being kicked downhill about 100’ or so, but didn’t result in any unexpected triggers. It was tedious, but I finally got up after about an hour of work, climbing 2 levels of boulders, then approached the summit block where I didn’t think my lack of progress and efforts would yield fruit and turned around; the risk was too high with the undisturbed pillows of powder on the N/E aspects and convex rollovers, in particular because it looked like I’d have to climb a cornice.
I took a slightly different path down from the saddle (just poking around), and found the melting behavior characteristic of wet loose conditions to be more widespread. Lots of tree bombs were continuing to fall at various points around the descent, so I tried to mind my surroundings; a smaller one fell on my head/shoulders earlier in the day while walking up the road.
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