Pro Field Report
Basic Information
Observation Details
Observation Date:
March 15, 2022Submitted:
March 15, 2022Observer:
SAC - Davis, VandenBosZone or Region:
Banner SummitLocation:
Cape Horn (All aspects, 6,500-8,700')Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
IsolatedCollapsing?
IsolatedSnow Stability
Stability Rating:
GoodConfidence in Rating:
ModerateStability Trend:
SteadyBottom Line
We did not encounter any sensitive wind slabs despite walking along a ridge exposed to the predominately S wind. That said, given the mix of wind-scoured surfaces, new snow + wind, and an icy crust I don't doubt they are out there.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
OvercastTemperature:
mid 30s FWind:
Light , SWNew/Recent Snowfall:
HST = 5 cm dense snow @ the highway, HST = 13-15 cm @ 8,500'It snowed S1-S2 on our tour, tapering by early afternoon. There were spots of blue and even a little sun in the N. Sawtooths on the way home. Some light rain near Red Fish Ck. Hard to say where the rain line was as it was clearing as I drove home. Best guess on Stanley side based on snow in trees is about 7,000'. Snow picked up again at the Pass. HST @ Titus lot was ~5 cm of dense moist snow. Snow turned to rain just past Galena Lodge at about Coyote Ck (~7,100') and oscillated between snow and rain until the SNRA. Mostly rain from the SNRA south but it was also beginning to clear.
Avalanche Observations
One very small dry loose sluff on a steep N-facing slope. It was running on the (3/8) rain crust, peeling the upper ~25 cm of snow from today and Sunday.
Snowpack Observations
HST = 5-15cm with elevation. Today's snow was separated from Sunday's snow by a thin crust up to at least 8,500'. The combined thickness of these snows above the (3/8) rain crust was anywhere from 5-31cm (thicker on shaded aspects, and as we climbed in elevation).
The PWLs produced ECTNs and did not show any obvious signs of instability where we traveled.
NNE, 8,000', HS = 215 cm, subtly wind-loaded slope:
ECTNs in recent snows since Sunday's storm.
ECTN15 and 9, down 31 cm below the (3/8) rain crust.
ECTN24 down 62 cm (likely 1/20), prying on the block produced a clean shear.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Wind Slab
|
|
Unknown | Unknown |
Comments: Not encountered directly. We observed some drifting and found surfaces that were obviously stripped of new snow. |
Terrain Use
We planned to avoid obvious wind slabs where we found them, particularly with the uncertainty of how the persistent weak layers near the surface would react to a new load.