Pro Field Report

Basic Information

Observation Details

Observation Date:
January 23, 2023
Submitted:
January 23, 2023
Observer:
SAC - Jon Preuss
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Spring Creek (W-N-S; 7000-10,400')

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced
I experienced cracking beneath my skis in recent wind-affect. The cracks weren't more than a few inches deep and didn't travel far.

Snow Stability

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

Bottom Line

The winds over the weekend removed much of the upper snowpack in this area. The structure of the snowpack looks poor with the firm over sugary facets or depth hoar. However, neither of those layers produced results in stability tests.

Media/Attachments

Numerous wet loose avalanches occurred on Boulder Peak from around Jan. 21st. Warmer temperatures and ambient sunshine helped trigger them.
Depth hoar found on a north-facing slope in the Boulder Mountains.

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light , N

Skies were broken in the morning and became overcast in the afternoon with light flurries. Ridgetop winds blew light with moderate gusts from the north.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
6 Boulder Peak
S 9,700' 		D1.5 WL N-Natural These wet loose avalanches likely occurred on Jan. 21st. Warmer temperatures and ambient sunshine helped trigger them.
Numerous wet loose avalanches occurred on Boulder Peak from around Jan. 21st. Warmer temperatures and ambient sunshine helped trigger them.

Snowpack Observations

The main objective was to look at the snowpack in the alpine. I dug numerous pits across a north face at 10,350' to look at varying slab thicknesses. The height of snow ranged from 66-100cm. A dense slab (1Finger to Pencil hardness) was sitting on top of chains of depth hoar. The extended column tests didn't show any signs of propagation (ECTN20s) within this layer.

Most of the starting zones were missing snow and were covered in rocks. I was able to dig in a couple of them safely. I found hard snow (1Finger to Pencil hardness) with facets below it. Most snow depths varied from 1-2 feet, with many visible rocks.

I dug another snow pit on a southwest-facing slope at 9000'. Various crusts were present, but none had instability in test results (ECTN20 on 1/5, ECTX on 12/19).

Depth hoar found on a north-facing slope in the Boulder Mountains.

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: 35-50cm
Comments: Rose is shaded to where problem was observed.
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
 Comments: Much of the recent storm snow was stripped over the surface. The surface was largely previously buried crust and large sastrugi.

Terrain Use

Avoided slopes over 35. The snowpack structure does not give me confidence in getting into bigger, consequential terrain.