Observation: NWAC Observer
Basic Information
Observation Details
Observation Date:
February 24, 2022Submitted:
February 24, 2022Observer:
NWAC Observer - Robin PenderyZone or Region:
Snoqualmie PassLocation:
Chair Peak & Mt. Roosevelt (ATL, NTL NW-NE aspects, all aspects BTL)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
IsolatedCollapsing?
None ExperiencedMedia/Attachments
Advanced Information
Weather Summary
Cloud Cover:
Mostly CloudyWind:
CalmNew/Recent Snowfall:
5 cm HNEast flow kept things generally overcast. Winds were calm, but there was significant evidence of previous wind transportation, particularly near ridgelines.
Several small dry loose avalanches triggered by daytime warming observed during the day. These were all D1 or smaller.
Snowpack Observations
We found surface conditions to be highly aspect dependent today.
On slopes affected by the sun, we found a thin breakable crust. When the sun was directly on these slopes, the surface quickly went from dry to moist. Luckily, the sky cover prevented any significant warming.
On NE-NW slopes at or near ridgelines, we found wind stiffened surface snow (5-10 cm of 4F snow above F ).
In sheltered terrain below treeline and off of ridges, you can still find soft settling powder.
At 4,800 ft on a NNW aspect in the Wildcat Lake Drainage, we found the 2/14 crust down 40 cms. This layer has small (1 mm) but defined facets above it. This layer was unreactive to tests. You can locate the 2/19 crust, but in this location it seems to be decomposing quickly. The late January crust is still present, but is trending twoards unconsolidated melt forms rather than a true crust.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Dry Loose
|
|
The avalanches we observed were clearly triggered by warming, but given the powder clouds I can't call them "wet loose". Given another hour of sunshine, we would have been in wet loose country.