Pro Field Report

Basic Information

Observation Details

Observation Date:
December 1, 2022
Submitted:
December 2, 2022
Observer:
SAC - Preuss, Davis, VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Butterfield (N-E-SE, 6760'-8150')

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Widespread
There were too many collapses to count.

Snow Stability

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

Bottom Line

In the small window of weather, we were able to visually confirm multiple crowns in prime time avalanche terrain. That observation was pretty impactful as there isn't a lot of avalanche terrain in this location, which is why we chose to travel here. On the drive home, there were many naturals in small, obscure pockets of forest. There is no question that is has been naturally avalanching over the last 12hours.

Media/Attachments

This small slope north of Baker creek avalanched as a skier approached it from the road above. The skier was approximately 20m away from the slope when they felt a collapse and watched this slope release. The slab failed on very weak, well-developed facets below the 70cm (2+ feet) of new snow. This slope faces NE at 8,500'.

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light , SW
New/Recent Snowfall:
HST 60-75cm

Cold front seemed to past through around 1100hrs with some wind and S2-3. There was a lull mid day, followed by more S2-3 on exit at 1600hrs.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Butterfield Creek
NW 7600' 		D1.5 SS O-Old Snow N-Natural It was flat light and challenging to make out the crowns until a clearing in the weather. The bed surface looked dark and appeared to spots the ground poking out. None

Numerous pockets of Soft Slabs along the Big Wood River (near Frostbite Flats) and on the N-NE slopes of Oregon Gulch facing the Big Wood River.

Snowpack Observations

If the numerous collapses weren't enough info, Ben had an ECT fail on isolation down 70cm. We did notice a supportable crust on a SE slope with a thin layer of facets on it. All E-N terrain had a healthy layer of 1-2mm FC that were F hard.

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: 60-70cm/1127
Weak Layer(s): Nov 27, 2022 (FC)
Comments: Many collapses on this layer on multiple aspects. We anticipate this layer at upper elevations as well (not directly observed).

Terrain Use

We methodically choose an area that had amble simple terrain to avoid the avalanche hazard for the day. We entered the field with an Assessment mindset and were looking to gain information on how the slab was consolidating and bonding with the underlying weak layer.