Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
April 12, 2023
Submitted:
April 12, 2023
Observer:
NWAC Forecaster - Andy Harrington
Zone or Region:
West South
Location:
Bullion Basin

Signs of Unstable Snow

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

Media/Attachments

Snow profile highlighting the moisture content of the upper snowpack.
In this location, the 4/11 melt-freeze crust was 6cm thick and mostly supportable to boots.
Cornices survived the atmospheric river and are still overhung in some locations. They'll need to come down at some point this spring.
Cracking and some small blocks failing on a wind-loaded feature near a ridgeline.
Recent wet avalanche debris in Bullion Basin was covered up by a few inches of new snow.
It only took a few sun breaks to start to moisten up the snow surface.

Advanced Information

Weather Summary

New/Recent Snowfall:
5-6" at upper elevations with considerably less down low

In and out of the clouds for most of the morning with a few snowflakes falling here and there. Minimal to no wind experienced.

There was plenty of recent wet avalanche debris spotted in Bullion Basin and the surrounding area. Most of these are suspected to have run during the latest AR event and all had new snow on top of them. No new avalanches were observed except a few Wet Loose avalanches on cutbanks on my drive down the boulevard.

Snowpack Observations

There is roughly 5-6 inches of new snow overlaying the 4/11 crust. I found the bond to be moderate to poor, but the snow lacked a lot of cohesion, so it was difficult to assess. The crust itself was fairly stout and whenever I stepped out of my skis, it was mostly boot supportable. In some locations, you would plunge through down to your knee or so. Moist snow exists under the crust and the wetting front was approximately a foot below the surface.

Near ridgelines, wind effect was present with deeper drifts, cornice build-up, textured surfaces, and wind sculpturing. I stomped on a few test features and got some cracking and small blocks to fail but didn't trigger any actual Wind Slabs.

On slopes that typically receive a lot of solar input, a breakable surface crust existed, likely from Tuesday afternoon. These same slopes showed some signs of moistening during sun breaks, but it never went full bluebird while I was out there today.

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