Pro Field Report

Basic Information

Observation Details

Observation Date:
December 30, 2022
Submitted:
December 31, 2022
Observer:
SAC - VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Baker Creek Drainage (6,700-9,700, primarily E-SE-S-SW)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
Avalanches observe refers to today's remotely triggered slide (details below). I experienced short cracking in fresh wind drifts and one collapse on a stiff wind pillow (in addition to the collapse the triggered the slide).

Snow Stability

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

Bottom Line

I remotely triggered a large avalanche from a safe ridgeline above. I also found weak layers in the middle of the snowpack that produced unstable snowpack test scores.

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Light , SW
New/Recent Snowfall:
12cm measured in Baker lot, presumably from today's storm.

Afternoon wx: there was a lull in the storm between around 1200 and 1500, with S-1 to S1 precip afterwards. Winds were light, but I could see active transport in the upper elevations of the Boulders and Smokys on my drive to the TH.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Dec 30, 2022
(Exact) 		Baker Ck - above Baker Lake
S 9500ft 		D2 HS-Hard Slab O-Old Snow 1.5ft AS-Skier
r-Remote
This large avalanche was remotely triggered from 400-500' away on the ridgeline above. It broke 1-2' deep on a S-facing slope at 9,500', failing on the weak snow near the ground that exists across the forecast area.This slope had been heavily affected by previous winds.
This large avalanche was remotely triggered from 400-500' away on the ridgeline above. It broke 1-2' deep on a S-facing slope at 9,500', failing on the weak snow near the ground that exists across the forecast area.This slope had been heavily affected by previous winds.
Report

I did not see any other avalanches, but the visibility was poor and I likely would not have seen anything in the adjacent terrain.

Snowpack Observations

My primary goal was to look at weak layers on solars in the upper snowpack, and to look at the amount of snow and any avalanche activity in the area since 12/26.

I found 12cm of medium-density new snow in the Baker lot. Near Baker Lake, I found 40-45cm of snow on top of the 2-3cm thick Christmas heat-wave crust. This snow was well bonded to the crust, which was essentially just a rigid portion of the upper slab in the snowpack.

SE @ 8400' : 12/19 down 50cm, produced ECTP 15,18, 23 and ECTPV (broke as I was sawing the column, I unintentionally levered on the saw when finishing the cut). 11/27 down 100cm, produced ECTP 21, 22, 34 (non-hulk smash, just additional shoulder hits). FC/DH at base of the snowpack were moist and showing signs of healing, but the upper portion of this layer (11/27) was still dry with 2-3mm striated cups.

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: down 50-65cm
Weak Layer(s): Dec 8, 2022 (FCsf) Dec 19, 2022 (FC)
Comments: Rose shaded based on where I was looking at this layer today, it likely extends down into lower elevation terrain. It may still also be problematic where associated with SH, but observations on this are limited.
Deep 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: down 100cm
Weak Layer(s): Nov 27, 2022 (FC)
Comments: Slab over this layer varies considerably in thickness, particularly in wind affected areas. Sensitivity appears to be a function of burial depth. In places where it is buried more deeply, this layer is gradually improving. In places where it is closer to the surface it is lingering and not improving.

I did not encounter wind slabs as a problem today, but visible transport in Boulders and Smokys and plenty of snow for transport leads me to suspect they are present in places.

Terrain Use

I avoided large, steep, unsupported avalanche terrain and the runouts of large paths.

BESbswy
BESbswy