Pro Field Report
Basic Information
Observation Details
Observation Date:
February 3, 2021Submitted:
February 3, 2021Observer:
SAC - Ethan DavisZone or Region:
Soldier and Wood River Valley MtnsLocation:
Wells SummitSigns of Unstable Snow
Recent Avalanches?
YesCracking?
IsolatedCollapsing?
WidespreadSnow Stability
Stability Rating:
PoorConfidence in Rating:
ModerateStability Trend:
SteadyBottom Line
Weak snow interfaces under our recent storm snow (1/27) and near the ground (12/11) produced widespread collapsing and poor snowpack test scores. Given the setup, I was expecting to remotely trigger an avalanche in nearby steeper terrain.
I did not observe recent avalanche activity around Wells Summit, but I did observe a large, fresh slide in Croy Canyon near Hailey (see photo).
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
Partly CloudyTemperature:
20 FWind:
Light , NWNew/Recent Snowfall:
HST = 10 cm (4 in)Very light snow flurries mid-day. Broken skies with clouds hanging in the Soldiers to the west, partly cloudy over the S. Smokys.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Photos | Details |
|---|---|---|---|---|---|---|---|---|---|
| 1 |
Feb 3, 2021 (+/- 1 day) |
Croy Canyon - Bullion/Democrat Divide E 7700ft |
D2.5 | N-Natural |
|
Report |
I didn't see any recent avalanches around Wells Summit but last night's snow and wind certainly made these harder to detect. I had a good vantage point and visibility from Big Peak down to the southern tip of the Smokys around Buttercup.
Snowpack Observations
Overall height of snow was generally near 80 cm although thinner on steep S-SW-W facing slopes. Some of these low elevation sunnier slopes were free from snow or at least had a lot of sage poking through again.
I found a reactive 30 cm thick persistent slab problem (1/27) on all aspects at 8,000'. Slabs failed above crusts in a layer of near-surface facets; numerous ECTPs with 5 taps or fewer. I looked hard for surface hoar and couldn't find any.
The December facet layer near the ground was quiet in snowpack tests, although I'll admit I was paying more attention to the near-surface problem. It did not produce results in ECTs. However, the largest/loudest collapse I experienced was certainly within this layer.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Layer Depth/Date: 25 cm Weak Layer(s): Jan 27, 2021 (FCsf) Comments: ECT's failed on isolation or 5 hits and fewer. Aspects painted where observed. |
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|
Persistent Slab
|
|
Layer Depth/Date: 50 cm Weak Layer(s): Dec 11, 2020 (FCsf) Comments: One loud, large collapse with boot pen on a south aspect. No notable results in snowpack tests. Aspects painted where observed. |
Terrain Use
I avoided avalanche terrain.