Observation: NWAC Forecaster
Basic Information
Observation Details
Observation Date:
March 3, 2023Submitted:
March 3, 2023Observer:
NWAC Forecaster - Dallas GlassZone or Region:
Snoqualmie PassLocation:
Commonwealth Basin/Cave Ridge (All Aspects Near and Below Treeline, 3000-5300ft)Signs of Unstable Snow
Recent Avalanches?
YesCracking?
None ExperiencedCollapsing?
None ExperiencedMedia/Attachments
Advanced Information
Weather Summary
Cloud Cover:
OvercastWind:
Light , NWNew/Recent Snowfall:
Storm snow (HST) 12-16 in (30-40cm), new snow while in the field ~3-4" (10cm)Stormy to start the day, became more showery, even with a few very brief sunbreaks mixed in. Lots of snow still falling.
We triggered and observed several natural loose dry avalanches. These slides remained small and didn't travel too far down slope.
Snowpack Observations
Wind Observations: Previous wind affect (drifts, wind lips, and cornices) from 3/2 could be seen but were covered with several (4-6") inches of soft snow. Test slopes did not produce any cracking, but the wind-affected snow was compelling.
3/2 Interface: The new snow is largely right-side-up. We found that if it were going to fail, it was frequently on a layer of graupel within the storm snow. Hand pits, hand shears, and shovel tilt tests often highlighted the layer of graupel. However, small slopes, uptrack tests, and snowpack tests did not show significant failures nor cracking. We also did not see any recent signs of slab avalanches during periods of better visibility.
2/25 Interface: This layer occasionally failed in snowpack tests (shovel tilt and compression), but was often rough and did not fail in larger column tests (ECT).
Other older snow layers: We could find other recent storm interfaces (2/27, 2/19 or 2/17). These layers appear to be gaining strength.