Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain

TUESDAY: Flurries with accumulations up to 10 cm, strong southwest winds, alpine temperatures -8C.WEDNESDAY: Cloudy with isolated flurries, strong northwest winds, alpine temperatures -8C.THURSDAY: Cloudy with isolated flurries, strong to extreme west winds, alpine temperatures -8C.

The recent low density snow produced numerous size 1-1.5 avalanches on Monday. These included loose dry avalanches releasing naturally and soft slabs triggered by skiers. Last week, explosive triggers also released several larger avalanches (up to size 2.5) running on weak sugary facets between 40 and 100 cm deep.Wind slabs remain the primary concern for human-triggering, as strong winds are forecasted to persist throughout the week and redistribute the low density storm snow. Persistent slabs releasing on weak layers that formed in early December are also becoming a concern, although there is some uncertainty as to how reactive they'll be. Recent explosive results suggest these layers could potentially wake up with extra loading from new snow or wind, or possibly be triggered from shallow snowpack areas.

Expect another 10 cm of new snow by Tuesday afternoon. A total of 20-30 cm of low density snow now sits above hard wind slabs, and will be redistributed by strong southwest winds. A variable interface that formed during the mid-December cold snap can be found 50-80 cm deep. This interface consists of hard wind packed snow in exposed terrain, weak faceted (sugary) snow, and surface hoar up to 20 mm in sheltered areas. This interface may evolve into a persistent slab problem once the storm snow settles into a slab. Deeper in the snowpack you may find another layer of surface hoar in sheltered areas or weak facets that were buried in early December. The thick crust from mid-November is near the bottom of the snowpack and reports suggest that the crust is currently well bonded to the surrounding snow.