Avalanche danger will increase rapidly as heavy snowfall blankets the region through Saturday. Stick to simple terrain that is free of overhead hazards - and enjoy the new snow!
Cornices have grown large and loom over many ridge lines. They have potential to fail as they are loaded with new snow and could also fail under the weight of a person or machine. Give them a wide berth.
Heavy snowfall is expected to drive the formation of new storm slabs throughout the day on Saturday. New snow is not expected to bond well with the current snow surface and wind will likely accelerate slab formation in open areas.
Up to 35 cm of new snow is expected to accumulate in the region by the end of the day on Saturday. The new snow will bury heavily wind affected surfaces in exposed areas as well as sun crust on solar aspects and temperature crusts up to 1700 m on all other aspects. The new snow is not expected to bond well with any of these surfaces over the near term.
A thick rain crust that has facets associated with it sits 30-60 cm below the surface and can be found up to ridgetops. We have only seen one avalanche on this layer since February 17th. The mid-pack is well settled and strong, but the base of the snowpack contains basal facets that are most prominent in shallow rocky start zones.
Friday night: Cloudy with increasing flurries bringing about 10 cm of new snow. Light to moderate southwest winds.
Saturday: Cloudy with continuing heavy snowfall bringing 15-25 cm of new snow. Moderate to strong south winds. Alpine high temperatures around -5.
Sunday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate southwest winds. Alpine high temperatures around -9.
Monday: A mix of sun and cloud. Light to moderate southwest winds. Alpine high temperatures around -8.
A few small loose avalanches were observed on sun-exposed slopes on Tuesday and Wednesday. Over the weekend a few small wind slab avalanches (see this MIN report) and size 2 cornice falls were reported. The cornice falls did not trigger any slabs on the slopes below.
Looking forward, heavy snowfall over Friday night and Saturday is expected to rapidly increase avalanche danger in the region as it accumulates and forms new storm slabs that bond poorly with the current snow surface.
