Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
December 17, 2021
Submitted:
December 17, 2021
Observer:
Chris Lundy
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Beaver Creek (8000-9400', snowpack obs from S-E-N)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
Isolated
One large collapse at 8300', NE

Snow Stability

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

Bottom Line

Weak October snow is buried more deeply in this area than further south - about 2.5-3+'. Snowpit tests and a large collapse indicate that this weak layer is still reactive, and any slide triggered would likely be quite large. Although recent storms obscured the details, there was a cycle of natural avalanches in this drainage during the storm. Southerly facing slopes at mid elevations had the best stability.

Media/Attachments

Recent wind slab in Beaver Creek. 9500', E.
Recent wind slab in Beaver Creek. 9500', NE.
https://youtu.be/OlIrRnO-ghs

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
teens
Wind:
Light
New/Recent Snowfall:
There appeared to be 15-20cm of snowfall from the past few days.

While temps were cold, there was enough sun for solar slopes to take a bit of heat at the surface.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
2 Dec 14, 2021
(+/- 1 day)
Beaver Creek
N 9600ft
D2 SS-Soft Slab O-Old Snow N-Natural
Look closely to see ghost crowns
Report
1 Dec 14, 2021
(+/- 1 day)
Beaver Creek
W 9600ft
D2 SS-Soft Slab O-Old Snow N-Natural
Report
Beaver Creek
Beaver Creek

There has been enough recent snow and wind to obscure details, but there appeared to be a cycle during the storm in this drainage. I also saw a ghost crown from a smaller slide in fairly sheltered terrain, and two small (~D1) wind slabs that released within the past day or so.

Snowpack Observations

@8100', SE, 27*: HS 70cm, no old October snow, right side up snowpack going to 1F- at the ground.

Large collapse @8300', NE. Facet/crust layer felt with a pole 75cm down.

@8600, E, 20*: HS 145cm. 90cm settled HST (bottom third 1F) on 12/11 crust/facet/crust layer. Facets were F+, 2mm. ECTP 26 on 12/11. See attached video.

Probing at 9300', N on semi-sheltered slope: HS 180-195cm, 12/11 felt 105cm down.

Beaver Creek snowpit at 8600', E.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Weak Layer(s): Dec 11, 2021 (FC)
Comments: Rose colored in on forecasted location

Encountered some freshish, deep, soft drifts, but they were small spatially and seemed unreactive.

Terrain Use

I avoided avalanche terrain.