Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
March 9, 2022
Submitted:
March 9, 2022
Observer:
SAC - Ethan Davis
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Apollo Ck (S-E-N, 6,600-9,600')

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced
Cracking (15-25 cm) in freshly forming wind slab. Mainly confined to at/near ridgeline in this location. No slab avalanches. 2 small loose snow avalanches that occurred yesterday? See below.

Snow Stability

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

Bottom Line

I did not encounter slabs large enough to be of concern, but it would not have surprised me in the right terrain.

Media/Attachments

This slide looked quite fresh, maybe yesterday? It's above Chocolate Gulch on a 6,700' SE facing slope. The Snotel hit 40 F there yesterday.
Pit on a S-facing low angle slope at 9,100'. 

The upper layer is new snow, followed by 3 prominent crusts with facets inbetween. 

There were anywhere from 2 to 4 crusts on sunnier slopes dependant on slope angle and aspect.
Pit on a NE-facing slope at 9,500' at the head of Apollo Ck in the Smokys. 

This location produced mixed results (ECTPs, ECTXs and ECTNs). 

The ECTPs were on the lower layer of near surface facets with possible shards of surface hoar.

The upper layer was a well defined layer of surface hoar. 

This was the ugliest setup I saw. I certainly would not want to encounter it where the slab was stiffer.
3mm surface hoar on the upper end of the obvious weak layer. This produced ECTN and ECTX.
This small freshly formed wind slab formed just below an exposed ridge on an E-facing slope at 9,600'.

These small slabs ranged from 15-25 cm thick in this location and tapered quickly.
ECTNs and ECTPs (6 and 7 taps) on small facets.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
Single Digits F
Wind:
Light , N
New/Recent Snowfall:
HST = 2-10 cm from Baker Parking Lot to Apollo

Mostly cloudy with some filtered sun. Very cold. Wind chill was frigid. Light to moderate wind from the N and NE. Flagging and obvious drifting/sifting at times at upper elevation.

Avalanche Observations

I saw two small loose snow avalanches. I think the one by Chocolate Gulch was likely yesterday afternoon. I saw another on an E-face at the head of Bluff Ck just over the Smoky Crest. It was unclear if that was from this morning's sun breaks or from yesterday.

Snowpack Observations

S at 9,100', low angle slope:
A mixed bag of crust and facet layers. The depth, thickness, and strength of these layers varied greatly depending on aspect and slope angle. ECTNs down 10 cm.

0-8 new snow with a thin layer of facets underneath.
8-10 crust with facets below.
10-15 small facet layer.
15-17 crust with facets below.
17-37 facets with perc. columns.
37-39 re-frozen meltwater (pooling layer)
39-> stronger P rounding facets

NE at 9,500':
A very weak upper snowpack. I would not want to encounter this setup where the slab was more uniformly dense. In this location, snowpack tests produced ECTXs and ECTNs in a layer of surface hoar on the upper obvious stripe and ECTNs and ECTPs (6 and 7 taps) on the lower stripe.

Pit on a S-facing low angle slope at 9,100'. 

The upper layer is new snow, followed by 3 prominent crusts with facets inbetween. 

There were anywhere from 2 to 4 crusts on sunnier slopes dependant on slope angle and aspect.
Pit on a NE-facing slope at 9,500' at the head of Apollo Ck in the Smokys. 

This location produced mixed results (ECTPs, ECTXs and ECTNs). 

The ECTPs were on the lower layer of near surface facets with possible shards of surface hoar.

The upper layer was a well defined layer of surface hoar. 

This was the ugliest setup I saw. I certainly would not want to encounter it where the slab was stiffer.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Comments: Hard to imagine not finding a wind slab in favorable terrain.

Terrain Use

I skied short steep slopes without an obvious recent wind load. I would have avoided upper elevation N-NE with any wind-press or recent loading.