Observation: NWAC Forecaster
Basic Information
Observation Details
Observation Date:
March 15, 2022Submitted:
March 15, 2022Observer:
NWAC Forecaster - Matt PrimomoZone or Region:
Stevens PassLocation:
Skyline/Moonlight (West, North and East aspects up to 5,300ft)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
IsolatedCollapsing?
None ExperiencedAdvanced Information
Weather Summary
Cloud Cover:
Mostly CloudyWind:
Moderate , WMostly cloudy but with periods of blue sky poking through. Temperatures were cool and breezy first thing in the morning, but became warm and steamy quickly with snow beginning to drip out of the trees.
Intentionally triggered a D1.5 wet loose slide on E at 5,000ft. The slide ran about 100 vertical feet. Also triggered a number of D1's in smaller terrain features.
Snowpack Observations
We could get isolated cracking on the new/old interface on steep rollovers on shaded slopes, but it seemed like the storm snow instability was settling out nicely by mid-morning.
Snow became noticeably more dry above 4,500ft or so, and we measured 20cm of new snow at 5,300ft, 30cm over the early March crust.
On a north aspect at 5,300ft: The 3/8 faceted layer was still weak, though had gained strength (What was Fist hardness was now 4F-1F), and now the grains were rounding and moist. CTM RP, and ECTN H on this layer. CTM failed down 20cm on the new/old interface (storm layers).
On an East aspect at 5,300f: I found 30cm of recent storm snow becoming moist, over a few different wet snow layers, with minimal results in tests. Ski tests were touchy, however, and easily set off wet loose slides on wet snow beneath the storm snow. Slides would run fairly fast and pack a punch once they got going. Slopes only needed to be about 35 degrees or steeper to run.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Wet Loose
|
|