Pro Field Report
Basic Information
Observation Details
Observation Date:
December 4, 2020Submitted:
December 5, 2020Observer:
Chris Lundy & Ben VandenBosZone or Region:
Galena Summit and Eastern MtnsLocation:
4th of July Lake (Primary snowpack obs from 9000-10700, N-NE)Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedSnow Stability
Stability Rating:
GoodConfidence in Rating:
HighStability Trend:
ImprovingBottom Line
Relatively stable snowpack, although weak facets near the ground from October seem prevalent in this area on upper elevation, northerly slopes. Despite the lack of recent loading, this layer looks ugly enough that I wouldn't want to be on a steep, consequential slope where it exists. On slopes where the October snow doesn't exist, the snowpack is right side up and no slab/weak layer structure exists.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
Mostly SunnyTemperature:
Strongly invertedWind:
CalmStrong temp inversion in place with temps ~30 F warmer up high than at the highway.
Avalanche Observations
Two small loose snow (likely wet loose) avalanches observed above Washington Lake.
Snowpack Observations
Snow depth past the 4th of July trailhead averaged 40-75cm. Even in the shallower areas, the snowpack was maintaining at least enough strength to be supportable on skis or sled.
@9450', NW, 19*, HS 75cm: top 20cm faceting. 11/17 dust layer obvious but no crust present. Most significant finding was a ~7cm layer of 3-5mm DH atop a weak MFcr at the ground (60cm down). In addition to looking ugly, it produced a ECTP22 and PST29/100end.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Weak Layer(s):
Nov 7, 2020 (DH)
|
Terrain Use
We avoided steep, upper elevation, northerly facing terrain due to the existence of the weak October snow near the ground.