Storm snow will continue to accumulate Friday night and through Saturday as a frontal system stalls over the region. This will raise the avalanche danger to HIGH.
A buried weak layer of surface hoar and possibly a crust can be found in the middle of the snowpack. While difficult to trigger, avalanches failing on this layer would be large.
Storm slabs will develop through Friday as snowfall accumulates around the region, adding to snow from early this week. Expect new storm slabs to develop, and be wary of recently developed slabs hiding under fresh snow.
25-45 cm of new snow falling over the past 36 hours has added to the 30-50 cm of storm snow from early in the week. All this new snow has covered a thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas around treeline and below.
A layer of surface hoar (feathery crystals) may be found in sheltered areas around treeline down 50-80 cm. In some areas this may be sitting on a crust.
A variety of crusts from late October are buried deeper in the snowpack. Total snow depths range from 120-150 cm around tree line.
Friday Night: Snow, 10-20 cm, alpine temperature -3 C, moderate southwest wind.
Saturday: Snow, 10-15 cm, alpine temperature -4, moderate southwest wind.
Sunday: Sunny with cloudy periods, alpine temperature -10, moderate north wind.
Monday: Sunny with cloudy periods, alpine temperature -8, moderate northwest wind.
Recent reports indicate skier triggered and natural storm slab avalanches to size 2, and cracking on small, supported slopes. There were also a few reports persistent slab avalanches failing on a layer of surface hoar (down 60-80 cm) at treeline elevations. Expect to see an increase in storm and persistent slab avalanches as the new snow continues to accumulate through Friday night and Saturday.
