Public Field Report
Observation Details
Observation Date:
December 11, 2022Submitted:
December 15, 2022Zone or Region:
Mores CreekActivity:
Skiing/SnowboardingLocation:
Whoop Um Up @ 6200ftObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
5800Aspect:
NComments:
Observed skier-triggered avalanche debris while driving home. Avalanche occurred near the road on a north-facing ridge close to the Rocky Ridge yurt (Lamar Creek drainage). Happened to see the guy walking back to his car, so all is well.Possibly also saw one other skier-triggered debris in the Winter Corner zone, but hard to tell while driving.
Signs of Unstable Snow
Observations
In light of the high/extreme forecast this weekend, I went for a short solo tour up the Whoop Um Up drainage for some mini-golf laps and to gather snowpit data. Pit data is from approximately 6200ft, NE aspect at around 11am on Dec 11th, 2022.
About 8-10" of dense snow fell in this zone overnight, winds steadily SE for the last few days. Wind slabs were prevalent but never felt unstable. Snowpack is fairly unconsolidated, boot penetration essentially bottomless. Aside from a few slab interfaces (seen below), pit data showed mostly 3-4 finger penetration all the way to the bottom, where it turns to rotting garbage facets from the bottom layer to the ground. There is a weak layer from an older interface about 1.5' from the ground, my column test failed on this layer, CT14. No propagation, but it clearly stepped down into the bottom facet layer.
No collapsing/whoomphing observed, and things generally felt stable. If I didn't know about that bad bottom layer I would probably have felt comfortable stepping into more consequential terrain, but, as my column test proved, it's not a good idea to test this snowpack right now. The bottom facet layer is about 1-3" thick and has not had nearly enough time/weight to begin consolidating. This will be a problem layer for a while, and in lower-elevation zones like this it goes all the way to the ground, meaning extremely high consequences.
Skiing was great. It's wild to have this much snow this early in the season, but as always I am shocked at the decisions some people make in the Mores Creek Summit area, and even more shocked at the lack of public data from this zone. This is arguably the most popular backcountry zone for Boise people, it only takes a few minutes to gather some data and post an observation. We're all in this together, come on everyone!
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