Pro Field Report
Basic Information
Observation Details
Observation Date:
January 3, 2022Submitted:
January 4, 2022Observer:
SAC - VandenBosZone or Region:
Soldier and Wood River Valley MtnsLocation:
East Fork Big Wood (6,100-8,800', NE-N-NW)Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedSnow Stability
Stability Rating:
GoodConfidence in Rating:
ModerateStability Trend:
SteadyAdvanced Information
Weather Summary
Cloud Cover:
OvercastWind:
Moderate , SWOvercast skies with the sun squeaking underneath for a few minutes around sunset. Light to moderate winds blowing up high, out of the SW/W. A few grains of rogue grains of graupel appeared in the late afternoon but just a passing blip. Temperatures felt quite warm, particularly in middle elevation terrain above the inversion.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Photos | Details |
|---|---|---|---|---|---|---|---|---|---|
| 2 |
Dec 30, 2021 (+/- 3 days) |
Mine Bender NE 8600ft |
D2 | SS-Soft Slab | N-Natural | Report |
Snowpack Observations
Went out to look at surfaces, mid-pack weak layers, and October snow.
Surfaces: widespread faceting of the snow surface. Where I traveled, this is best developed at lower elevations (below the inversion) and upper elevations. I was in somewhat dense trees through much of the middle elevation band so that may help explain that. I found SH on the surface similar to that reported in my ob from Trail Creek yesterday, but it was a bit spottier in distribution. I suspect the winds had knocked a bunch of it down. Despite cold temperatures the sun had built RadRx crusts on solar slopes steeper than about 33. These may be the most concerning surface.
Mid-pack weak layers: I was on cold aspects throughout my tour and observed fairly obvious buried FCsf at the interface between the two big storms, now down 40cm. This produced rough shears and ECTNs and ECTXs and did not look quite as concerning as I've seen elsewhere. This fits with the pattern of spotty distribution of these layers. The pattern of where these do and don't exist has been tricky to pin down, but they are concerning where they exist.
October snow: 12/11 FC/DH now buried down 90cm underneath slab that grades from F down to 1F- (by 60 down) and then to 4F/4F+ at the base (slab is faceting from top and bottom). I dug just as I was getting into enough of this snow to connect across ground roughness, at 7,900' on a NE facing slope. HS=100cm. Received ECTP 23, 24, and 26 in my three tests.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Weak Layer(s):
Dec 11, 2021 (FC)
|
Terrain Use
Continuing to avoid avalanche terrain that holds October snow at the base in this Forecast Zone.