A persistent weak layer exists in certain terrain features in the alpine. Layers like this are unpredictable and hard to out-smart. This problem could be around for a while and an overly cautious approach to large, connected, north-facing alpine terrain is prudent at this time.
Small amounts of new snow could be deposited into small wind slabs in steep alpine features. This will be a reverse-loading pattern as winds are forecast to be from the north this week.
Buried weak layers continue to produce large, surprising avalanches in alpine terrain. Although uncertainty remains around the extent and distribution of this layer, the recent avalanche activity has been observed on steep, north to northeast terrain. Keep in the mind the potential for remotely triggered avalanches and how far these large avalanches can run into flatter terrain. Also keep in mind that stiff slabs can pull back into flatter terrain above them. These layers will be easier to trigger where the snowpack is thinner.
A couple of large (size 2-3) persistent slab, human-triggered avalanches have been reported over the weekend. Avalanches have occurred near ridgetops in north-to-northeast alpine terrain. Both avalanches have shown an impressive capability of propagating large distances. Here is a link to the most recent human-triggered size 3 avalanche.
Uncertainty remains about the distribution and extent of the problem.
If you are out in the backcountry please consider filling out a Mountain Information Network report.
In alpine terrain, recent winds have created a variety of wind-affected surfaces. New snow and wind will create thin wind slabs in exposed terrain features. Recently formed hard surfaces and surface crusts had new surface hoar and facets on top before being buried. This new layer should be monitored closely moving forward.
Persistent weak layers of surface hoar and/or facets exist in north facing alpine features behind ridge lines, creating a number of recent, scary human-triggered avalanches.
Below roughly 1700 m a widespread, supportive, melt-freeze crust is present, with moist snow below.
Tuesday night
Cloudy with light snow, 2 to 5 cm. Treeline temperatures -5 to -10 C. Moderate northeast alpine winds.
Wednesday
Cloudy, no precipitation. Treeline temperature -15 to -20 C. Moderate northeast alpine winds.
ThursdayCloudy, no precipitation. Treeline temperature -15 to -20 C. Moderate alpine winds.
FridayA mix of sun and cloud. No precipitation. Treeline temperatures -15 to -20 C. Light northeast winds.
More details can be found in the Mountain Weather Forecast.
