Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Andrew Kiefer
Observation Date:
March 7, 2021
Submitted:
March 7, 2021
Zone or Region:
West North
Activity:
Snowmobiling/Snowbiking
Location:
Canyon Creek

Signs of Unstable Snow

Did you see shooting cracks? 
Yes, Isolated
Did you experience collapsing or whumpfing? 
No

Observations

Traveled to Excelsior and Bearpaw via snowmobile. Parked at the Canyon Creek bridge at 2100ft, but continuous snow began near 1800ft. Gusty southerly winds blew throughout the day with brief periods of moderate snowfall (S2) mixed with a few sun breaks. A noticeable uptick in the height of storm snow occurred at 4000ft, with 45cm (18in) of settled, right-side-up snow well bonded to the March 4th crust. No evidence of recent natural avalanche activity. Significant wind loading near and above treeline with blowing snow throughout the day. Small, shallow slabs of wind drifted snow were stubborn to trigger. Observed numerous snowmobile tracks in steep wind-loaded features with only one triggered wind slab (D1) on a convex roll >35 degrees. Stability tests targeting the recent storm snow did not produce concerning results with resistant planar fractures and no propagation. A very large glide crack that formed earlier in the season on a SE aspect at 4800ft near Cowap Peak significantly widened over the past week (photo below).

Media

Wind loading and growing cornices on a north aspect at 5200ft
Test pit in Excelsior above Damfino Lakes
Cornices on Bearpaw Mountain
A pre-existing glide crack widened significantly over the past week (SE aspect, 4800ft)
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