Pro Field Report
Basic Information
Observation Details
Observation Date:
February 22, 2021Submitted:
February 23, 2021Observer:
SAC - VandenBosZone or Region:
Galena Summit and Eastern MtnsLocation:
Butterfield (6,800-9,600')Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedBottom Line
Found several crusts with adjacent facets that produced unstable snowpack test scores.
Advanced Information
Weather Summary
Cloud Cover:
Mostly CloudyWind:
Strong , WIncreasing cloud cover in the afternoon, with a few S-1 showers after 5pm. Ambient air temps were in the mid 30s F at lower elevations, estimated near 30 F at upper elevations
Snowpack Observations
Went looking for the presence and character of crusts on solar aspects in this area. I found 3 prominent crusts in the snowpack in my pit, dug at 8,500' on a S/SE aspect where HS=90-100cm. Pretty hard to be certain on the timing of these crusts. There was a thin MFcr with adjacent facets down15-20cm that produced a few ECTNs in the single digits and a single ECTP 6. A stouter, 2-3cm P MFcr with facets below (down 45-50cm) produced an ECTP 18 and 20, and ECTNs with moderate force. A third crust was found down 60cm, best guess is that this is the solstice rain crust? The 12/11 interface, which presents as 3-5mm depth hoar buried 65-70cm down, produced an ECTP 20 and 22 and ECTNs with hard force.
Significant snowpack warming and snowpack consolidation in the upper portion of the snowpack today. Expecting to find 3-5cm thick MFcr on direct solars and solar margins (wasn't entirely refrozen when I encountered it). It may have been warm enough to melt the surface on shaded slopes at lower elevations today, but I didn't encounter that directly.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Layer Depth/Date: down 65-70cm Weak Layer(s): Dec 11, 2020 (FCsf) Comments: Rose shaded for where problem was encountered |
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|
Persistent Slab
|
|
Layer Depth/Date: down 45-50cm Comments: Rose shaded for where problem was encountered |