Avalanche Forecast

Fair - Intensity of incoming weather systems is uncertain

Tonight and Friday: A trace amount of flurries overnight with freezing levels returning to valley bottom. Daytime cloudy with light to moderate accumulations of 4-10 cm with higher precipitation focused in the southern parts of the region. Moderate winds at ridge top from the south west. Alpine high around -4 with freezing levels rising to 1000-1200m.Saturday: A break between systems will bring briefly clearing skies and freezing levels rising to 1500m in the south and 1100m in the northern parts of the region. Alpine highs expected between -1 and -5. Ridge top winds light to moderate out of the south west. Light to moderate precipitation starting in the evening.Sunday: A mix of sun and cloud with a few light flurries and freezing levels rising to 1000m.

Yesterday a size 2 avalanche in the south eastern part of the region was triggered below treeline and caught and carried a skier. The slab was on a south east aspect, was 40 cm deep, and ran on on a combination of sun crust and facets beneath the storm snow. Several explosive, skier controlled, snowmobile triggered, and natural avalanches and cornice falls sizes ranging from 1 to 2.5 have been reported on various aspects and elevations.

Forecasted new snow amounts between 4-10 cm are expected to vary across the region with greater accumulations in the south. This precipitation will combine with the current 20-40cm of recent storm snow, creating slabs 25 to 80cm deep in the alpine and treeline, primarily in wind loaded start zones. Shifting winds between the north and south west have loaded various aspects at upper elevations, creating touchy wind slabs characterized by smooth pillow-like deposits of wind textured snow. Storm slabs may be easy to trigger due to poor bonds with underlying surfaces which include old hard slabs in the alpine, sun crusts, and several layers of facets and surface hoar in sheltered areas at treeline and below. The mid snowpack is strong and supportive. A deep persistent layer of facets and depth hoar has remained dormant to this point, but may become a concern with additional load and stress on the snowpack. With the forecasted precipitation and wind it may take a while to stabilize the snowpack so we can expect avalanche occurrences to continue over the next three days.