Pro Field Report

Basic Information

Observation Details

Observation Date:
January 27, 2022
Submitted:
January 30, 2022
Observer:
SAC - VandenBos
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Grays Peak (6,300-10,500, SW-W-NW-N)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

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

Advanced Information

Weather Summary

Cloud Cover:
Clear
Wind:
Light , NW

Clear and fairly cold all day. Light winds blowing out of the NW

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
6 Jan 6, 2022
(+/- 1 week) 		East Fork Big Wood River
N 8500ft 		D2 HS-Hard Slab N-Natural
This slide failed on a N facing slope at 8,600' near the boundary between the Galena Summit and Soldier and Wood River Valley Forecast Zones.
This slide failed on a N facing slope at 8,300' near the boundary between the Galena Summit and Soldier and Wood River Valley Forecast Zones.
Report
East Fork Big Wood River

Observed widespread avalanche activity on N-NE-E slopes from storm in first week of January (and maybe earlier)?

Snowpack Observations

Widespread buried SH at lower elevations (down 3-6cm). Intense faceting of the upper snowpack at all elevations. Even below the level of the inversion the snowpack is still ski/boot/sled supportable above the 30cm of very-well developed facets in the upper snowpack, which seems somewhat uncommon. I'd imagine the combination of a stiffer surface underneath and a facet stack at the surface could make for some impressive persistent slides in sheltered terrain when (if) we get another big storm. Surfaces at upper elevations are a range of slick/icy/faceted/wind-whack, about what you'd expect given the weather we've had. All of these could make for variably long-lived weak layers when snow returns.

Dug at 8,600' on N facing slope where HS=120-140 cm. Shovel shears revealed a few clean shears in the upper 1/2 of the snowpack, but no response in ECT. 12/11 DH+MFcr is buried 90-100cm down, returned ECTP 32 and 33 (non-standard loading steps, but not hulk smashes, just more hits from the shoulder) and CPST 32/100 and 37/100 END. DH grains are showing little signs of healing, though the layer of concern seems to be thinning a bit. However, grains are still cupped and striated in the 2-3cm weak interval sandwiched between old ambient-temp melt-freeze crusts. As I've observed in other portions of this zone, this weak layer is very capable of coming out of dormancy with additional loading and could still be triggered in the wrong terrain with a healthy dose of bad luck.

Snowpit dug at 8,600' on N-facing slope above the East Fork of the Big Wood River, near Grays Peak.

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
 Weak Layer(s): Dec 11, 2021 (FC)
Comments: Rose shaded based on where problem is known to exist. Sensitivity somewhere between stubborn and unreactive.

Did not encounter wind slab problem today, but did not go looking for it. All slabs I saw were firmly bonded and quite hard.

Terrain Use

Avoided shaded terrain where 12/11 was present at the base of the snowpack. This was a fairly easy decision as most northerly slopes had taken a serious beating from the wind.