Pro Field Report
Basic Information
Observation Details
Observation Date:
February 21, 2022Submitted:
February 22, 2022Observer:
SAC - VandenBos (off duty), GallZone or Region:
Sawtooth and Western Smoky MtnsLocation:
Copper (6,600-9,000', primarily NW-N-NE)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
None ExperiencedCollapsing?
None ExperiencedSnow Stability
Stability Rating:
GoodConfidence in Rating:
ModerateStability Trend:
Advanced Information
Weather Summary
Cloud Cover:
OvercastWind:
CalmNew/Recent Snowfall:
HST = 10cm, HN12 = 2-3cm at upper elevation, 1cm at highway levelA few hours of partly cloudy to mostly cloudy skies in the morning, then cloud cover increased around noon, creating mostly cloudy to overcast conditions. Cloud cover was thin, with occasional, very small windows of clear skies visible through the cloud deck. Winds were calm all day long. Snowing S-1 to S1 on and off throughout the afternoon, without a ton of accumulation, about 2-3cm at upper elevation.
Avalanche Observations
The only avalanches we observed were small, dry loose sluffs that we intentionally triggered in steep terrain. These were easy to trigger and easy to manage.
Snowpack Observations
10cm of low-density new snow since the morning of 2/20 for a total of 15cm of snow on top of the V-day crust (formed 2/9 and buried 2/14, this is the most obvious landmark in the upper snowpack). There was a bit of wind drifting and sifting in exposed, upper elevation terrain, but the effects were confined to near ridge lines and the snow hadn't been blown into much of a slab, mostly just a pile of low density snow. The deepest drifts we encountered on top of the Valentine's day crust were up to about 30cm thick, right along the ridge. These were unreactive to ski cutting.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Dry Loose
|
|
Layer Depth/Date: down 10-15cm Comments: Specific to very steep terrain with a dense surface underneath. These picked up speed quickly but never really entrained much debris. |
Wind slabs could have been more of an issue if they were larger, more widespread, and more reactive, but since they were so small and so isolated I wouldn't call them a problem. I put dry loose on the list because they were easy to trigger, but they were also small and easy to manage.
Terrain Use
We felt comfortable in steep terrain, but were on the lookout for small wind slabs and the consequences of being caught by a small, fast-moving sluff.