A weak layer of sugary facets is sitting on top of a crust layer buried 1-2 foot down. Recent natural avalanches have proved these south facing aspects to be suspect. Shady slopes have a worse looking layout and a weak layer getting buried further into the snowpack. Keeping away from avalanche terrain remains the only solution to such a widespread problem.
Cirrus clouds moved out of the area after 1300. There was lots of sunshine in the afternoon hours with light winds.
Dec 11, 2022
(+/- 1 day)
West Fork Prairie Creek
|D2||U||I-New/Old Interface||N-Natural||There is also an old avalanche that may have failed during the beginning of the storm on a SW aspect at 10,200' in the middle bowl of this photo.|
The West Fork Prairie Creek naturals confirmed there is an instability on some south facing aspects. My snowpits today confirmed it was likely failing on the new/old interface of 12/8.
Layer Depth/Date: 50-90cm
The southerly facing avalanches observed appear to have failed on the 12/8 layer buried ~50cm down. There is certainly less avalanche activity occurring on south slopes, but that doesn't make them any more appealing to hop on right now. The W-N-E avalanches could be failing on either of the past weak layers (11/27 and 12/8) depending on the grain type and/or size. It is challenging to tell from the crown depths being far away. If there was surface hoar present in the recent n/o, I would imagine that to fail easier than the deeper layer (11/27). In this area, the deeper layer (11/27) was more concerning because of the poor structure and lack of a reactive n/o layer. The 11/27 layer is pushing 90cm deep with a beefy slab on top of it.
Closed avalanche terrain and was mindful of remote triggering slopes above.