Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
January 17, 2020
Submitted:
January 17, 2020
Observer:
SAC - Martin Stefan
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Central Boulders

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
Isolated
Cracking and collapsing on wind stiffened snow from mid elevations and up in open areas

Snow Stability

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

Bottom Line

Buried weak layers from New Years still show signs of straining under wind/storm slab from mid elevations and up, especially where the wind has been loading.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
mid 20s est
Wind:
Light , NW

An inch of snow overnight, lots of wind transport at higher elevations on Smoky crest and in the Boulders, from NW.

Snowpack Observations

At lower elevations the storm slab is in some areas resting on thin crust, that gave collapses and cracks. HS around 70cm and bottom of snowpack under crust completely faceted out.
As I got higher the crust disappeared, and the storm slab rested straight on top of 40cm FC in sheltered areas. Where the wind had got to the snow there were isolated pockets of DF under stiffer windskin/windslabs that produced collapses and cracks.

9000' S relatively sheltered HS 100cm
20cm DH at gnd
12/31 @ 50cm FC 2mm under varius generations of windslabs mostly 4f and topped off with 25cm right side up storm snow, 4f->F
ECTP13q1 PST30/100 end on 12/31
No signs of 12/7, might have faceted out where the snowpack is this thin.

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: 12/31, 40-100cm
Comments: Depth based on both today and previous days. 12/31 seems to be the most pronounced persistent problem in this region right now, but deeper layers are still there in some areas too.

Terrain Use

I avoided avalanche terrain