Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
March 29, 2022
Submitted:
March 29, 2022
Observer:
SAC - Davis
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Baker/Brodie Divide (All but W, 6,700-9,700')

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced
See photo of wet activity near the Baker Divide.

Snow Stability

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

Bottom Line

The snowpack is draining/refreezing at a slow rate. Crusts broke down and I was skiing slop by midday on steep, sunny slopes. A good solid clear, cold night will dramatically change this picture moving forward. Dry, slab avalanches seemed unlikely.

Media/Attachments

Wet loose activity in "Spin the Bottle" near the head of Baker Ck in the Smoky Mountains. Avalanche activity was on ENE-E-SE facing slopes at about 9,700'. There was a similar slide on a NNE-facing slope at 9,500' on Baker Pk.
Baker Ck TH
Looking back toward the Boulders on Baker Ck Rd. The road is passable but there is only about 8-12" of packed snow on the groomed trail.
This is the weak layer responsible for the rider-triggered slides near the head of Baker Ck on March 18th. The weak layer still looks bad (dry F+ facets) on some aspects straddling due north.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
Upper 30s F
Wind:
Moderate , NE

Some light rain this morning near the SNRA. A thick cap of clouds on the Boulders, likely lightly raining fairly high given the temps. I didn't see any accumulation (in the trees) at any point. Moderate wind from the N and NE. Hot in the sun but wind kept it bareable. No snow moving.

Snowpack Observations

I went back to the area where riders triggered a persistent slab above Brodie (Baker Ck Drainage) on March 18th to see how the persistent weak layer here fared during the heatwave.

Overall Impression: My sense is that triggering a slide in this same sort of terrain is unlikely, even where the weak layer stayed dry. I think we're talking about a very limited chunk of terrain where this might still pose an issue, namely very steep slopes >9,500' that face NNW-N-NNE. Even here the slab has sat for 10 days and is faceting.

NNE @ 9,500-9,700': The weak layer was still preserved, dry, and weak (fist facets). I imagine it's similarly weak on N and NNW as well. The slab is ~35 cm thick and faceting (4F). Snowpack tests showed propagation ECTP around 10 taps but I couldn't get any cracking when stomping around above the pit.

ENE (70 deg) slope @ 9,500': Immediately adjacent to these pit results above, I found moist/wet snow and large percolation columns (to full arm depth). Anything with a kiss of sun was pushing lots of water through the weak layer.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wet Loose
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Comments: Shaded where observed + expected. There was a decent corn window on S and SW before ~11 AM. Anything facing the sun was getting mushy/punchy after that. There is still a lot of water sitting in the snowpack. Crusts were 10-20 cm thick (open sky view) but breaking down by midday with glop underneath. Wind helped keep things a little cooler at upper elevations.
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Comments: ECTP10 down 35 on FC, NNE @ 9,700'

Terrain Use

I would have avoided very steep terrain on NNW-N-NNE greater than about 9,400' given the poor snowpack structure. The weak freeze was worse than I expected. I would have avoided classic, sunny, wet loose terrain in the afternoon.