Weather Forecast
Today expect a mix of sun and cloud, with cool temps of -15 to -20, and light winds at ridgetop. A low pressure system will move into the region overnight. Tomorrow will be cloudy, with light snow (up to 5cm), and a high temp of -10. Over the weekend expect flurries, light to moderate W winds, and temps ranging from -10 to -4.
Snowpack Summary
Up to 80cm of settled snow sits over a variety of surfaces like surface hoar at lower elevations, facets and variable wind slabs at higher elevations. This interface is reactive in snowpack tests. Strong winds have formed wind slabs and wind loaded pockets at treeline and above. Below this are 2 persistent weak layers and the snowpack is facetted.
Avalanche Summary
Avalanche activity has tapered off now that the storm is over. A widespread natural avalanche cycle occurred over the past 3 days, with avalanches up to size 3.5 being triggered by rapid loading by snowfall and wind transport. Most were initiated in the alpine and at treeline, running well into runouts, but several triggered slabs below treeline.
Confidence
Intensity of incoming weather systems is uncertain
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.