Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
December 27, 2020
Submitted:
December 28, 2020
Observer:
SAC - VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Titus Ridge

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
single digits to low teens F (estimated)
Wind:
Calm , N

Light winds blowing out of the N-NE-E at the weather station. Dead calm elsewhere. Lots of incoming solar radiation, but cold temps were preventing crust formation on all but steepest slopes that directly faced the sun.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
2 Dec 26, 2020
(+/- 1 day)
West Fk Prairie Peak
E 9500ft
D2 SS-Soft Slab N-Natural Report
1 Dec 26, 2020
(+/- 1 day)
Saviers Peak
E 9800ft
D2 SS-Soft Slab N-Natural Report
1 Dec 26, 2020
(+/- 1 day)
Parks Peak
E 10000ft
D2.5 SS-Soft Slab N-Natural
Large natural avalanches are visible on McDonald Peak (foreground) and Parks Peak (background). These slides broke hundreds of feet wide, failing at the end of the storm on Saturday.
Report
West Fk Prairie Peak
Saviers Peak
Parks Peak

Snowpack Observations

My primary goal was to look at the skier-triggered avalanche that occurred on 12/26. I ultimately did not feel comfortable entering the terrain without a partner due to concern of overhead hazard. Based on photos and location, it appears that the slide failed on the thick layer of early-season facets that were initially buried on 12/11.

I continued along the ridgeline to the weather station, glassing for avalanche activity along the way. I observed recent large, natural avalanches in the Headwaters, Smilley, and Alturas drainages, as well as on McDonald and Parks Peaks. On the drive north, I observed recent large, natural avalanches in the Owl Creek and Prairie Creek drainages.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Weak Layer(s): Dec 11, 2020 (FCsf)
Comments: Location based on pattern of natural activity and previous observations.

Terrain Use

Avoided avalanche terrain for ease in decision making and lack of partner.