Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
December 30, 2019
Submitted:
December 31, 2019
Observer:
SAC - VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Pole Creek to 10,000'

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
Isolated
Isolated cracking and collapsing at lower elevations in flat terrain where 12/7 SH was present and pre-12/7 snow coverage was thick enough to fill in gaps between sagebrush and rocks.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Stability Trend: 

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
mid 20s at highway, low teens (est) at upper elevations
Wind:
Light , N

Beautiful clear day. Calm to light north winds at ridge tops. Sun broke down previous days crust, upper 2cms became moist.

Avalanche Observations

Evidence of loose snow avalanches (solar initiated dry loose) from past week. No distinct slabs observed.

Snowpack Observations

HS=40-70cm, strongly affected by wind, elevation and aspect. Difficult to find a representative slope for digging, thanks to amount of sage brush and rock near the surface. 12/7 widely distributed, overlying slab still thin enough here that I'd expect it to re-activate with additional loading.

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: In a state of dormancy, thanks to faceting of overlying slab
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Comments: Wind slabs I encountered were restricted to ridgelines and unreactive, mostly a concern based on additional stress on weak snow underneath