Pro Field Report
Basic Information
Observation Details
Observation Date:
January 28, 2021Submitted:
January 28, 2021Observer:
SAC - Ethan DavisZone or Region:
Soldier and Wood River Valley MtnsLocation:
Greenhorn, E. Fork Bigwood (All aspects, Low elevations)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
WidespreadCollapsing?
WidespreadSnow Stability
Stability Rating:
Very PoorConfidence in Rating:
HighStability Trend:
SteadyBottom Line
I observed natural avalanches on several of the low elevation N-facing slopes that I could get eyes on in the E. Fork of the Bigwood Drainage. Collapsing and cracking just beneath the new snow was widespread on a short walk at the mouth of Greenhorn. Storm slabs in non-wind affected terrain were 70 cm (28 in) thick.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
OvercastTemperature:
31 FWind:
Light , SENew/Recent Snowfall:
HST = 70 cmSnowfall rates at or just below an inch an hour. Easterly outflow drainage winds were drifting snow at low elevations in E. Fork. Snow intensity diminished on the drive back to Hailey around 2 PM.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Comments | Photo |
|---|---|---|---|---|---|---|---|---|---|
| 10 |
E. Fork Big Wood N 6,000 |
D1.5 | SS | S-New Snow | N-Natural | Poor visibility. I couldn't see above 6,000'. |
|
Snowpack Observations
Greenhorn, 5,800', N:
130-60 F/F-, Storm snow
60-58 4F, (1/13) MFcr, fragile and heavily faceted. Responsible for cracking and collapsing.
58-35 F, facets
35-30 4F, (12/11) MFcr.
30-GR F-, depth hoar
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Storm Slab
|
|
Layer Depth/Date: 70 cm/ Jan. 26 Comments: Weak melt freeze crust with facets above and below. No surface hoar found. Rose is shaded where problem was observed. |
Terrain Use
I avoided avalanche terrain.