Pro Field Report
Basic Information
Observation Details
Observation Date:
December 14, 2019Submitted:
December 14, 2019Observer:
SAC - Stefan - LinnetZone or Region:
Galena Summit and Eastern MtnsLocation:
Boulder mtn foothills along Silver CreekSigns of Unstable Snow
Recent Avalanches?
None ObservedCracking?
IsolatedCollapsing?
IsolatedSnow Stability
Stability Rating:
FairConfidence in Rating:
ModerateStability Trend:
SteadyBottom Line
There is both buried surface hoar and facets on crusts in some places, but the snowpack is still very thin and varies a lot over small distances and aspect changes. Stability is right now very hard to judge by just looking from a distance. The ongoing wind loading on east facing slopes and cross loading at higher elevations does not make the puzzle easier to solve.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
Mostly SunnyTemperature:
20Wind:
Moderate , NW12-16" of new snow from 12/11, and the wind was doing work moving it around above 7000ft. Clear signs of cross loading at mid and high elevations the Boulders.
Snowpack Observations
Big spatial variations in snowpack structure, even ignoring the ongoing wind loading. Buried SH were widespread above 7250ft on various aspects from NW through S to SE. In some places only shards and scattered remains, in others they were still standing on top of a crust. I could not make a clear pattern w.r.t. aspect or elevation, but we were on very low angle slopes.
At 8500ft S facign slope there crust both from 12/11 and 12/7 (see picture) with FC on one MFcr and SH mixed with FC on the other. Both produced results on ECT and we had collapses in the area. There was clear variability even within the snow pit, the 12/11 crust for example was only present in half of my pst column.
Fresh wind slabs were prone to producing 1-2ft shooting cracks, especially if there was some form of crust in the underlying snowpack.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Layer Depth/Date: 11/12 Comments: Fc or SH on MFcr, buried either 12/7, 12/11 or both. Presence at mid and higher elevation in the Boulders is assumed from weather and observations in other areas. Distribution might range from isolated to widespread with elevation and aspect, as will potential avalanche size.. |
|||
Wind Slab
|
|
Unknown |
Comments: Clear signs of cross loading at mid elevation in the Boulders and the foothills. Potential for stepdown into SH or FC from 12/11 or 12/7. |
Terrain Use
We avoided avalanche terrain