Northwest Avalanche Center

Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
March 29, 2023
Submitted:
March 29, 2023
Observer:
NWAC Forecaster - Matt Primomo
Zone or Region:
East Central
Location:
Blewett Pass-Tronsen Head

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced

Media/Attachments

South facing slopes near treeline still have great coverage.
Cross drifting above the road at Rock Slide.
Large cornices still loom over much of the steeper terrain off Tronsen Head.
Skin track tests showed isolated areas of cracking like this.

Advanced Information

Weather Summary

Cloud Cover:
Overcast
Wind:
Light

Broken skies with a breeze in the first half of the day, becoming calm later with overcast skies, and notably warmer.

Snowpack Observations

I found 2-5cm of newer snow covering the recently groomed road. Evidence of the recent east wind event was noticeable on many open, exposed slopes near treeline or near a ridgeline. Areas of thin wind slab and wind crust were scattered and isolated. Other surfaces were soft, settled powder in the shade, or just the new snow over a supportable sun crust elsewhere.

Skin track tests and my downhill track would sometimes create small fractures on wind stiffened surfaces.
From what I gathered, it seemed quite possible to trigger small wind slabs on very steep slopes.

By 2pm, snow surfaces were warming on all aspects but I didn't observe any signs of wet loose avalanches. It didn't really seem like the set up for it was there with mostly wind touched surfaces, and only a few cm's of new snow.

Coverage is still quite good in the area, even on solar slopes near treeline. Lower elevation south aspects are melting out around rocky and treed areas though.

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