Pro Field Report

Basic Information

Observation Details

Observation Date:
December 1, 2022
Submitted:
December 1, 2022
Observer:
SAC - Lundy, Leidecker
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Cross (rec tour) (8500-9200', E & NW)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
Cracking was isolated overall but widespread in any wind drifted/stiffened areas

Snow Stability

Stability Rating: 
Poor
Confidence in Rating: 
High
Stability Trend: 
Steady

Bottom Line

Loading from new snow and wind is overloading an exceptionally weak snowpack. Slope >35* with any wind effect/stiffening seemed likely to slide. Wind-sheltered slopes had less of a cohesive slab, but would likely slide on slopes approaching 40 degrees.

Media/Attachments

Cracking in wind-drifted terrain near the tope of the Cross on Galena Summit
Avalanche above Camp Creek on HWY 75 en route to Galena Summit.
Avalanche above Camp Creek on HWY 75 en route to Galena Summit.

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Moderate , S
New/Recent Snowfall:
50-60cm storm total on the 11/27 interface

HST was fairly low density and did not seem particularly inverted. The wind was affecting open, mid-elevation terrain leading to a slightly stiffened surface. Significant amounts of snow was being drifted along exposed ridgelines, with drifts in excess fo 60cm observed. S1-2 throughout our tour from 1200 to 1600.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
2 Dec 1, 2022
(Exact) 		Above Hwy 75 between Titus Lake TH and top of Galena Summit
SE 8800ft 		D1.5 SS-Soft Slab O-Old Snow 1.5ft U-Unknown
Avalanche above the very top of Galena Summit that occurred between 11am and 4pm on Dec 1. May have been plow-triggered or occurred naturally.
Avalanche above the Titus Lake Th near the top of Galena Summit that occurred between 11am and 4pm on Dec 1. May have been plow-triggered or occurred naturally.
Report
Above Hwy 75 between Titus Lake TH and top of Galena Summit
 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
5 Road cuts above highway 75, especially below and above the highway uphill from Camp Cr hairpin
NW 8300 		D1 SS O-Old Snow 40-50cm (est) Unknown if plow triggered or natural None

No visibility of upper elevation terrain.

Snowpack Observations

New snow on wind-sheltered slopes was generally low-density and right-side up (except for weak facets below).

@8700', E: HS 100cm. HST 55cm. Base of HST was F+. 11/27 presented as thin/deteriorated/soft crust with some perc channels below it atop 40cm of F FC going to 4F at the ground. ECTN10 and ECTP11 on 11/27.

@8800, NW: HS 105cm. HST 55cm. 11/27 interface to ground was completely faceted, ranging from F at 11/27 interface to ~4F at ground. ECTP11.

We only observed cracking in wind-affected terrain, where it was widespread.

Snowpit on the Cross. E, 8700.

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: 55cm
Weak Layer(s): Nov 27, 2022 (FC)
Comments: Rose indicates terrain where we directly observed the problem.

Terrain Use

We avoided avalanche terrain