Observation: Avalanche Professional

All Observations

Basic Information

Observation Details

Observation Date:
March 6, 2023
Submitted:
March 7, 2023
Observer:
Avalanche Professional - Trevor Kostanich
Zone or Region:
Snoqualmie Pass
Location:
Mt Snoqualmie (3100-6200, All Aspects)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

5500', N, D2, debris ran 800 vertical feet, likely triggered from smaller natural wind slab above
4560', N, D2, crown up to 3'
5560', NE, D1.5, assume natural but notice ski tracks
Cornice NE of Snoqualmie E's summit
Corrnice NE of Snoqualmie's E Summit and small wind slab below cliffs

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light , SE
New/Recent Snowfall:
Hn settling to 15-20cm ski pen

Morning started with broken skies transitioning to overcast. Light SE winds near and above treeline, moderate at times along alpine ridges. No precip.

Observed 5 old winds slabs all on north aspects and high in terrain (4560'-6000'). All believed to be natural from Saturday morning (March 4th) with one possible skier triggered. Of note, was one old wind slab seen lower in the terrain (4560') that pulled out 60m wide with a crown height up to 3'. Started in steep convexity but deeper crown (wind deposit) than expected that low on the slope (slope starts ~6200'). Also observed a bigger than typical cornice NE of Snoqualmie's E Summit. See photos and captions for more info.

Snowpack Observations

Some cracking in wind deposited areas and minimal snow transport off summit ridgelines and over convexities above tree line. Still lingering wind slab concerns above tree line.