Observation: NWAC Observer
Basic Information
Observation Details
Observation Date:
February 18, 2022Submitted:
February 18, 2022Observer:
NWAC Observer - Robin PenderyZone or Region:
Snoqualmie PassLocation:
Alpental Valley (BTL, NTL, all aspects)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
None ExperiencedCollapsing?
None ExperiencedAdvanced Information
Weather Summary
Cloud Cover:
Partly CloudyWind:
Light , WMore sunshine than expected! Sky cover was scattered to broken, and at ridge tops we found light west winds. There was no blowing snow.
Avalanche Observations
| # | Date | Location | Size | Type | Bed Sfc | Depth | Trigger | Photos | Details |
|---|---|---|---|---|---|---|---|---|---|
| 3 |
Feb 17, 2022 () |
Alpental Valley S ft |
D1 | N-Natural | Report |
Small wet loose avalanches from midweek observed on sun affected slopes.
Snowpack Observations
Below treeline, surface conditions are variable. We found some areas of firm, frozen snow, slush, and preserved dry powder.
Near ridgeline and on other open slopes, we found a variably thick surface crust on all aspects. On true north aspects, this crust is easily breakable and still makes for pretty fun skiing. On aspects that see even a hint of sun, the crust is thicker and more challenging to initiate a turn in. Slopes that recieve direct sun became moist during the day, and we saw active roller balling in steep terrain.
At 5,100 ft on a NW aspect we found 40 cm of snow above the January 31 crust. 10 cm from the surface you can locate the Valentines Day crust. This crust was boot supportable in some areas, and makes travel on specific steep slopes difficult.
Beneath the Valentines Day crust, we found small (l.t. 1 mm) faceted grains. These grains were reactive to compression tests but did not show indications of propegation in extended column tests, likely due to the stiff crust they are beneath. The grains appear to be rounding.
Above the January crust, we found larger but irregularly dispersed 1 mm faceted grains. These seem to be much more rounded than they were at the beginning of the month, and were unreactive to tests.