Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
January 1, 2022
Submitted:
January 1, 2022
Observer:
SAC - Scott Savage - OFF DUTY REC DAY
Zone or Region:
Soldier and Wood River Valley Mtns
Location:
Indian Creek (W/SW-W-NW-N-NE: 5900-8100')

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced
I had a couple cracks travel a few feet when kicking small cornice/stiff wind drifts (but not hard slabs) on an exposed middle elevation ridge - not really worth noting above.

Snow Stability

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

Bottom Line

I didn't find any old October snow where we considered being in avalanche terrain. Where we traveled, we saw no signs of instability in non-wind-loaded terrain. We avoided the obvious, isolated wind-loaded features on steep slopes in this area. Where we traveled, avoiding wind-loaded slopes dramatically reduced the chances of getting in trouble. In the larger nearby drainages (Big Wood, Croy, Quigley, etc), there was more evidence of wind in the past 48 hrs; the S face of Carbonate looked like a ski area yesterday, and the wind obliterated the tracks overnight.

Media/Attachments

Obvious wind effects and hard wind slabs on an exposed , N-NW aspect around 7900' in the Indian Creek drainage near Hailey.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
Near zero F
Wind:
Light
New/Recent Snowfall:
No new snowfall.

Winds were calm for the most part. There is a moderate amount of snow available for transport, but I think winds would need to change directions or increase to STR-EXT speeds to move a lot of snow.

Snowpack Observations

+/- NW up to 6500': HS=30-50cm, fair amount of faceting in the lower half of the snowpack, no slab to speak of, small SH on surface
7400' W/SW 35* slope (see pit image): HS=50-60cm, thin crust (wind, but not sure?) below about .5cm of PP, then DF 4F>1F for the upper half of the pack, then matrix of 3 crusts with some FC and mixed forms between/above/below them (12/19-22 layers), then mostly RG 1F and P except some FC/mixed forms closer to the ground: ECTN13 @ upper of 3 crust/FC interfaces (Q2), ECTN21@ ground (Q3)
7800-8200 NW-N: wind hammered sastrugi with some hard slab rollers in typical cross-loaded areas (photo), no cracking or collapsing when jumping around on the hard slabs in mellow terrain, didn't sound as hollow as I expected they would have. I didn't dig to look for old Oct snow here, but there's a good chance there was some in this "zone".
7000-7800' NW-N-NE (minimal wind effects in this area): HS=consistent 70-80cm, well-graded snowpack. Layers near the ground and near the surface appear to be losing some hardness/faceting. 12/19-22 layer was much more subtle than on solar aspects - no crust, but some faceting. I did not look for SH with a lens, but there were no large SH particles. Partner was cold, so no formal stability tests performed. Hand tap tests and pulling/shear tests (both on isolated small columns) required moderate force to get borderline Q1/Q2 shears on mid-pack interface. There isn't much weight or stiffness in the snow/slab above the potential mid-pack weakness.

Snowpit on a WSW facing slope at 7400' in Indian Creek drainage near Hailey. Total depth is 50-60cm (about 2 feet).

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Layer Depth/Date: 10-30cm
Comments: Shaded area in Location graphic is where we observed recently wind-loaded slopes. Hard slabs were unreactive. The softer slabs at/near corniced areas were stubborn to unreactive and were more isolated as well as smaller in areal coverage (extending only 10' downslope). Minimal cracking in softer wind slabs, and no cracking in the hard slabs.

Terrain Use

We traveled in non-wind-loaded terrain up to around 35*. We planned to avoid wind-loaded terrain and all slopes with old Oct snow, and we stuck to that plan.