New snowfall overnight will add additional load to the recently formed windslabs observed on lee features at treeline and above. Strong winds in the forecast will result in further loading and increased sensitivity to human triggering.
Confidence
Fair - Intensity of incoming weather systems is uncertain
Weather Forecast
Light snowfall began late afternoon with up to 15cm possible overnight and into Wednesday AM. Winds are forecast to be strong to extreme resulting in some redistribution of storm snow onto lee features.
Avalanche Summary
no new observed or reported
Snowpack Summary
Test profile on a north aspect at TL highlighted a prominent weakness at the interface between the old surface crust and the recent storm snow. Compression tests showed easy to moderate results down 77cm. Numerous large and small settlements observed at treeline on a variety of aspects.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.