Avalanche Forecast

Moderate - Intensity of incoming weather systems is uncertain

MONDAY: Cloudy with light flurries, accumulation 5-15 cm, light to moderate southwesterly winds, alpine temperature near -6 C, freezing level near 1000 m.TUESDAY: Cloudy with light flurries, accumulation 5-15 cm, light to moderate southerly winds, alpine temperature dropping to -10 C over the day, freezing level below valley bottom.WEDNESDAY: Partly cloudy with intermittent flurries, light to moderate southwesterly winds, alpine temperature near -12 C, freezing level below valley bottom.

Storm slab avalanches have been reported, being triggered by natural triggers and skier activity. The slabs were small to large (size 1 to 2) and generally observed around treeline and alpine terrain with depths of about 20 cm. One release occurred in a loaded lee slope near ridgetop.Please share your observations through the Mountain Information Network.

Around 20-30 cm of new snow fell on surface hoar in sheltered slopes and a sun crust on steep solar aspects and may not bond well to them. The snow also fell with moderate southwesterly winds in the alpine, which could have produced small wind slabs in lee features.The new snow could create a dangerous slab above buried weak layers. Numerous persistent weak layers exist deeper in the snowpack. Dry snow overlies three layers composed of weak and feathery surface hoar, with the deepest layer (December 15) buried 30 to 60 cm. This layer is shallower in the north of the region and deeper in the south of the region. The weak layer is found most often at treeline and below treeline. As the snow above the weak layers becomes more cohesive and forms a slab, the setup has the potential to create easily-triggerable destructive slab avalanches.Deeper in the snowpack at depths of about 70 to 100 cm, a rain crust from November is producing variable snowpack test results, from sudden fracture characters to no result. This layer is considered dormant but could be triggered where the snowpack is thin.