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Missoula Avalanche

Professional Observation

Basic Information

Observation Details

Observation Date:
January 19, 2022 - January 19, 2022
Submitted:
January 19, 2022
Observer:
WCMAC - Todd Glew
Zone or Region:
Central Bitterroots
Location:
Little St. Joe

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
We triggered numerous small dry-loose avalanches in 30+ degree terrain today. There was 3" (7cm) of new snow that had not yet bonded to the melt-freeze crust it fell on, creating easily triggered fast-moving avalanches.

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
High
Stability Trend: 
Improving

Bottom Line

We were most concerned with how the new snow was bonding to the old snow on southerly facing aspects. We found that the new snow had not yet bonded to the old snow. We easily triggered dry-loose avalanches on slope angles above 30 degrees. We carefully managed our avalanche concern on the steeper sections of our descent.


Media

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light , NW

It was lightly snowing in the mountains at 7:30 am when we started our day. We experienced high clouds and light winds out of the NE.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
Numerous Today Little St. Joe- S Facing Gully
S 8500-6500
D1 L I-New/Old Interface 3" (7cm) AS-Skier
c-Intentional
We triggered numerous loose-dry avalanches in terrain over 30 degrees on our descent.

Dry-loose avalanches should not be as much of a concern tomorrow on this slope because the new snow will have had time to bond to the melt-freeze crust that it fell on.

Snowpack Observations

We dug multiple snow-pits on different aspects and elevations. Our pit results showed no propagation on rounding surface hoar and near-surface facets, buried about 1-2' deep (30-60cm).

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
None Specified

Terrain Use

We carefully evaluated the snowpack today because neither of us had ski toured around Little St. Joe this season. We dug several snow-pits on different aspects and elevations and did not find any propagation. After finding stable results in our snow-pits, our main concern focused on how the new snow was bonding to the old snow surface. My first ski cut in steep terrain showed that dry-loose avalanches were easy to trigger. We managed the new snow instability by making ski cuts in steeper terrain to avoid getting caught in carried in an avalanche.

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