Pro Field Report
Basic Information
Observation Details
Observation Date:
December 23, 2022Submitted:
December 23, 2022Observer:
SAC - Jon PreussZone or Region:
Galena Summit and Eastern MtnsLocation:
Johnstone Creek (All aspects up to 8000')Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
IsolatedCollapsing?
IsolatedSnow Stability
Stability Rating:
FairConfidence in Rating:
HighStability Trend:
ImprovingBottom Line
The new/old (12/19) may have been a recent player in the Winter Solstice wind storm. I observed this layer to be standing surface hoar with light density snow guarding it from above. I found surface hoar (12/19) in all three of my pit locations today. It was most sensitivity where it is overlaid with dense slabs from the wind. The basal facets (11/27) are showing signs of rounding, but are still far from me feeling warm and fuzzy about getting into avalanche terrain.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
ObscuredWind:
LightNew/Recent Snowfall:
HN: 1cmOvercast in the AM with on/off S-1. The afternoon had an hour of snow (S1). Winds were very light and variable.
Snowpack Observations
Today I wanted to observe surface conditions and the aftermath of the Winter Solstice wind storm. Sage is beginning to rear it's head with recent snow removal from wind, solar melt, and settlement from storms. The sage is most noticeable on sunny and west slopes that have a plethora of crust-facet sandwiches with minor to no connectivity of a weak layer.
I targeted a recently wind-loaded east aspect with 30cm of P to 1F hard slab on top of surface hoar (12/19). Results showed the recent wind slab to be more sensitive than I was anticipating with CT1 (SC), ECTP12,13. It appears this might take some more time to heal where it rests on top of a persistent weak layer. None of the structure looked great, but it appears the basal facets (11/27) are SLOWLY rounding. The top of this layer is resisting the rounding the most and is still threatening.
I couldn't pick out the rain crust (12/12) in any of my pits. I know it exists here, as I saw it on the south slopes, at the bottom of the upper melt freeze. Either I'm missing it or it has faceted enough to barely pick out. I don't think wind removed it from the East or North aspects.
The Johnstone area falls in between the Wood River Valley and Eastern Mountains zones. I haven't spent much time in the Pioneers, but the snowpack I observed here is similar to what I have been seeing across the Wood River Valley Zone.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Wind Slab
|
|
Layer Depth/Date: 37cm/1219 Comments: Sensitivity is more like Reactive-Stubborn. Tests failing on surface hoar (12/19). Shading depicts where I observed snow structure. |
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Persistent Slab
|
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Layer Depth/Date: 76cm/1127 Weak Layer(s): Nov 27, 2022 (FC) Comments: Rose is colored based on snow coverage in this particular area and what I observed. |
Terrain Use
I gave hard slabs a wide berth along ridgelines, knowing there is potential for them to break further back on the ridge. I avoided avalanche terrain due to poor structure.