Pro Field Report
Basic Information
Observation Details
Observation Date:
January 23, 2020Submitted:
January 23, 2020Observer:
SAC - Lundy, StefanZone or Region:
Soldier and Wood River Valley MtnsLocation:
Morgan RidgeSigns of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
IsolatedSnow Stability
Stability Rating:
GoodConfidence in Rating:
HighStability Trend:
ImprovingBottom Line
The snowpack in the lower and middle elevation terrain we traveled through consisted primarily of bottomless facets and depth hoar. Avalanche hazard was limited to where there was still a stronger slab over this weak snow—this was almost exclusively where old, hard wind slabs existed in exposed terrain. These wind slabs became more common and larger in size as you went up in elevation.
Advanced Information
Weather Summary
Cloud Cover:
Partly CloudyWind:
LightNice day with a few high, thin clouds.
Avalanche Observations
Saw a couple small, older slides that fit the patterns we've already seen.
Snowpack Observations
Snowpack observations were from 6100-8500'. Snow coverage on solar aspects in this elevation range is thin to nonexistent. On sheltered slopes with no wind effect, the snowpack was 40-60cm of bottomless facets and depth hoar, making uphill and downhill travel a challenge. As discussed in the bottom line, avalanche hazard is limited to where past winds have created hard slabs over the facets—which is common along ridgelines and downhill counters/sub-ridges.
@8000, NNE: this was below a ridge crest in an area with previous wind loading. The 65cm snowpack consisted of about half 1F wind slab and half F FC and DH. ECTP21 down 45cm—this actually broke in the middle of the thick basal facet layer on the 12/7 FC and SH, the SH crystals were clearly visible. But I could see it breaking anywhere in the bottom 30cm of the snowpack. We got a medium-sized collapse when we jumped hard on a snowpack with a similar structure to this.
Still not sure triggering an avalanche would be likely even in these areas, it feels pretty "dead", but I wouldn't bet my life on it.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Layer Depth/Date: 20-50cm Comments: Limited to areas with previous windloading. More common as you climb in elevation. |
Terrain Use
We skied terrain in the low 30s where there was clearly no slab. We avoided slopes steep enough to slide where we felt a hard/supportable wind slab underfoot.