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Missoula Avalanche

Professional Observation

Basic Information

Observation Details

Observation Date:
March 9, 2022
Submitted:
March 9, 2022
Observer:
WCMAC - Trask Baughman and Ryan Sorenson
Zone or Region:
Seeley Swan
Location:
Pyramid Peak

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Steady

Bottom Line

Today we rode sleds into Pyramid Peak in the Swans. We observed conditions from 5800ft to 7800ft on westerly aspects. We found 5 inches of low-density snow over a hard crust. Above 6500 ft, we found high spatial variability in snow depth due to strong east winds in the last 24 hours. We found 2-5 foot deep fresh wind drifts on the northwest side of ridges. We had three large collapses on the westerly ridges line, the kind that makes your heart race. Wind hardened snow over facets atop the rain crust was the probable culprit.

Overall we saw a complex picture due to variable winds in recent days. Variations in the mountain landscape have funneled winds causing drifting, cross-loading, upslopes winds, and various loading patterns for all aspects. Generally, the snowpack from before the rain event last week is locked up in this zone. However, the new snow and wind drifts have formed over slick crusts that may harbor facets on top.

Other observations made:
• In steep west-facing cliff bands, we observed loose dry coming down later in the day.
• We observed a recent slide from the summit, most likely from the last 48hours. We estimated that it ran 800ft downhill and was D2 in size on an SSW aspect, around 8000ft.

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Weather Summary

Cloud Cover:
Mostly Sunny
Wind:
Light , E
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