Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
December 28, 2019
Submitted:
December 28, 2019
Observer:
SAC - Savage (off duty - with family)
Zone or Region:
Soldier and Wood River Valley Mtns
Location:
Lake Ck - Triple Peaks: mostly N-W, 6200-8200'

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

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

Bottom Line

Buried surface hoar present, no obvious signs of instability. No recent wind-loading or cross-loading in this location on shady side below ridgeline. Differences between what we saw/experienced and the other Professional Observation from Triple Peaks this afternoon highlight how dramatically a little wind-loading can change stability over short distances. We saw plenty of bad structure, but good stability for now...all bets are off when this area sees a good storm.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
Teens F
Wind:
Light , W

Light winds on ridge 7800-8200', calm below that. Previous wind loading confined to near/at ridgeline, and no wind-loading below ridge recently (tracks were not blown in on N side of ridge, including tracks from 12/24). Soft snow is still available for transport on N side of ridgeline.

Snowpack Observations

Buried 12/7 SH layer present on shady slopes, some FC mixed into it as you drop in elevation. No cracking or collapsing today, traveling in non wind-loaded N-W terrain predominantly without tracks. New crop of 3-5mm SH on surface from valley floor to the top. Generally soft snowpack, lacking much of a slab.

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
Layer Depth/Date: 12/7
Comments: Sage and undergrowth sticking up through the SH and into the soft slab above it once you are 10m below the ridges. Elk were smashing up the starting zones from 7800-8200', no results.

Terrain Use

We stayed off wind-loaded starting zones and stayed on slopes <32*.