Pro Field Report
Basic Information
Observation Details
Observation Date:
February 12, 2023Submitted:
February 12, 2023Observer:
SAC - Jon PreussZone or Region:
Soldier and Wood River Valley MtnsLocation:
Shaw Mountain (NE-S; 6300-9600')Signs of Unstable Snow
Recent Avalanches?
YesCracking?
None ExperiencedCollapsing?
None ExperiencedBottom Line
The snowpack looks strong in much of the terrain covered today. The only outlier was on a south-facing slope where the 12/19 layer could produce propagating results with extra force. It seems unlikely to be able to cause avalanches with the makeup of the slab.
Media/Attachments
Advanced Information
Weather Summary
Cloud Cover:
Mostly SunnyWind:
Light , WToday's temperatures felt warm, and the solar input was melting snow on sunny slopes into the upper elevations. Mostly clear skies until thin bands of high clouds moved in the afternoon.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Comments | Photo |
|---|---|---|---|---|---|---|---|---|---|
| 2 |
Warm Springs Creek SW 8100 |
D1 | WL | N-Natural | They initiated underneath a rock outcropping with a >35 degree slope below. | None |
Snowpack Observations
My objective was to look at the stability in the upper elevation of this zone. The snowpack structure on the NE-facing slopes looked good, and the snow depths were 150-190cm, with no glaring signs of instability. All three of the snow pits had a layer of facets 2-3cm thick down ~20cm but didn't have enough of a slab on top of them. One location around 9200' depicted more of a weathered alpine area where the snowpack was more shallow (85cm snow depth). The entire slab was one-finger hardness with occasional pencil-hard sections sitting over a 10cm thick layer of rounding depth hoar (F+ 5mm). Extended columns needed some healthy "boot taps" from above to propagate.
A south facing snow pit at 9350' was 85cm deep, and an ECT propagated twice with 31 hits. A very dense pencil-hard 43cm (1.5 feet) slab sits over this layer, and it was challenging even to isolate it properly. It seems unlikely that this could produce an avalanche. Referencing Ethan's 1/17 observations from this area, the results of his tests were propagating at 17 and 23 hits. It is important to note that some of the ECTN15 (down 15-23cm) weren't crossing the column and need to be monitored for when more of a cohesive slab builds above those layers.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
|
|
Layer Depth/Date: 42cm/1219 Weak Layer(s): Dec 19, 2022 (FC) Comments: Rose reflects terrain observed. |
No reactive wind slabs were encountered. Slabs were mostly soft and faceting.
Terrain Use
Solo travel. I avoided skiing on avalanche terrain.