Two main problems:
1. Weak snow at the surface that is about to be buried by this weekend's storm. There is enough snow in many locations to establish a well-connected weak layer and the possibility for avalanches once loaded. Avalanches failing on this interface could step down to weak snow near the ground
2. Weak snow buried by Thanksgiving storms. This weak interface has not strengthened since Thanksgiving. The main difference now is that it has a slab on top of it.
Calm and clear all day. A few upper level stratus clouds passing through in the afternoon. Strong inversion in the morning, weakened through the day, but didn't mix out entirely.
|1||Within the past week||
NW Bowl Galena Peak
|D2||SS||O-Old Snow||N-Natural||Mid-storm avalanche, existence based on pile of debris in the bowl that was not there before the storm. No crown visible. This bowl was holding weak, faceted snow from storms in October.|
The last 4 days of inverted temps and clear skies have been quite hard on the snowpack. Snow surface has weakened significantly by several near surface faceting processes. Additionally, a widespread coat of surface hoar has been painted in most areas open to the sky. Crystals up to 3cm observed, averaging 1-1.5cm. Solar aspects cooked enough to build a crust (4F+ to P- depending on aspect and slope angle). Facets observed both above and below this crust.
Thanks to a shallow snowpack depth (40-80cm) the interface between early season snow and Thanksgiving snow has not strengthened appreciably.
|Interface buried by Thanksgiving storms.|