Pro Field Report

Basic Information

Observation Details

Observation Date:
November 23, 2022
Submitted:
November 24, 2022
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Soldier and Wood River Valley Mtns
Location:
East Fork Big Wood (6,500-9,500', primarily northern half of compass)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated

Bottom Line

The thin, weak snowpack that I encountered was capable of producing collapsing and avalanches. In most areas, the slab was lacking. But along high, exposed ridges, hard slabs were sensitive to my weight and I was able to trigger several avalanches.

Media/Attachments

This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
7-day weather history for Baldy showing uptick in wind speeds beginning late Tuesday and continuing through Wednesday.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Wind:
Light , NW

Light winds with short periods bumping into the low end of moderate, blowing out of the NW. Mostly clear skies with some streamers and bands of high stratus clouds. It may have snowed a touch of graupel here at best.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
3 Nov 23, 2022 5:00 pm
(Exact) 		near Grays Peak
E 9000ft 		D1.5
R1 		HS-Hard Slab O-Old Snow 1.5ft AS-Skier
r-Remote
This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
This avalanche was remotely triggered from the ridgeline above. It failed on weak snow near the ground in an area with a thin, wind-affected snow pack.
7-day weather history for Baldy showing uptick in wind speeds beginning late Tuesday and continuing through Wednesday.
Report
near Grays Peak

I did not observe any avalanches aside from the ones I triggered.

Snowpack Observations

This observation comes from very close to the border between the Galena Summit and Eastern Mtns zone and the Soldier and Wood River Valley zone.

Surfaces: an impressive coat of widespread surface hoar exists in this area. In most locations, the SH xtals are 1-3cm and standing tall. I found these from the valley bottom to at least as high as 8,700'. As it sits right now, this is the "best" layer of SH I've seen in this region in my short time here. If it gets buried in its current state it will certainly be able to produce avalanches once it has a slab on top.

Snowpack: down in the inversion zone the entire snowpack has faceted (F to F-). As you climb, the mid-pack begins to show a bit more strength, but not a ton (4F to F+). Travel would likely be significantly more difficult on skinny skis.

Triggered avalanches: I remotely triggered 3 slides from the ridgeline. All 3 appeared to have failed on very well-developed facets (2-4mm xtals of depth hoar with striated cups). The layer of DH was 2-5cm thick and sat on a stout melt-freeze crust that was glued to the ground. A very stiff, dense slab sat on top of this weak snow. The slabs that failed were localized to near the ridgeline and tapered to nothing within about 30m of the ridge. The bed surface of the larger slide had lots of grass and sagebrush poking through it. More information is available by looking at the avalanche occurrence entry for these slides.

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: Recently formed hard slabs near and along ridgelines.
Persistent Slab
Isolated
Specific
Widespread
 Unknown
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Weak Layer(s): Nov 1, 2022 (FC)
Comments: October snow. Low confidence on rose shading, rose is shaded based on where problem is expected to exist in this area.

Terrain Use

Avoiding avalanche terrain where slabs exist over weak snow.