Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain on Thursday

THURSDAY: Scattered flurries, accumulation up to 5cm / Wind light west. Alpine temperature -10 FRIDAY: Scattered flurries, accumulation a trace. Wind light southeast. Alpine temperature -10 SATURDAY:  Scattered flurries / Wind light northeast. Alpine temperature -9

Recent reports are limited to both natural and human triggered loose dry avalanches in steep terrain to size 1 in areas that have not been affected by wind. Expect continued potential for triggering loose dry avalanches in steep terrain and consider the potential to trigger persistent slabs where last week's storm snow has settled into a cohesive slab.

Last week's storm brought 30-50cm of new snow to the region. Predominantly northwest winds have since redistributed this storm snow into wind slabs in lee terrain at higher elevations while cold temperatures have inhibited slab formation elsewhere. Cold has also worked to decrease the cohesion and reactivity of older wind slabs.The storm snow lies over a variety of old surfaces, including large surface hoar (weak, feather-like crystals), sun crust and sugary facets. The bond at this old snow interface is of critical importance where the overlying storm snow has consolidated into a slab. The most concerning areas are those that saw pronounced surface hoar development before the storm, such as sheltered areas at and below treeline. Recent snowpack tests show wide ranging reactivity at this interface but suggest that it may be most reactive on northerly aspects. A crust which was formed by rain in late November remains a major feature in the snowpack and is down approximately 60-100cm at tree line elevations. This interface shows good signs of bonding in the Purcells, but has indicated some reactivity in steep, variably loaded alpine features in adjacent regions.