Quick report
- Red Flags
- Heavy Snowfall, Cracking, Collapsing, Poor Snowpack Structure
- Red Flags Comment
- <p>We got a few collapses and some cracking. We were also able to intentionally trigger a couple of small avalanches on test slopes.</p>
We traveled as high as 8,000 (Dead Tree) and found sensitive storm slabs on northerly aspects where the old snow surface was all near-surface facets.
There was no wind-drifting where we were, but the winds were stronger above 8,000' and it is possible you can find sensitive drifts at the upper elevations.
The PWL seems to be more of an issue at lower elevations where the snowpack is weaker. Once you get above 7,500' the storm snow was less reactive.
Photos of cracking and small avalanches on test slopes where the storm snow failed at the interface with the old snow surface, running on a temperature crust in some places.
Video discussion of intentionally triggering an avalanche on the test slope.
Video of extended column test - we repeated the test and the results were ECTP5 and ECTP9, failing down in the faceted snow at the old snow surface. The slab was soft (F+ hard) and in areas with a stronger slab, avalanches may propagate more widely and could also be remotely-triggered.
Snowpack
- Instability Comment
- <p>The storm snow bonded poorly to the old snow surface which consisted of near-surface facets. The snowpack was weaker below 7,000' and almost entirely faceted in some places. Once you got above 7,000', the old snow surface was weak, but had a stronger slab at the mid-pack. I have greater concerns for the PWL below 7,000' as the snowpack is weaker.</p>
Wet, heavy snow at Cutler TH with lighter snow above 7,000'
Storm snow 15-25 cms (6-10") above 7,000' and the denser snow is providing excellent travel and riding conditions as it cushions you from the old snow surface.