Conditions are variable across the Purcells. In isolated areas, a persistent weak layer may still be reactive to human triggers. Take the time to investigate your local snowpack.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
A cool, dry spell is starting. Expect light northerly winds, sun and slightly milder temperatures in the alpine; and cloud and cold temperatures in the valleys.For more details check out https://avalanche.ca/weather.
Avalanche Summary
Over the last few days, several small loose dry avalanches and one size 1.5 wind slab have been observed. Persistent slabs were last triggered about a week ago. Unfortunately these types of problems don't heal quickly, so they remain on our radar.
Snowpack Summary
20-30 cm of low-density snow typically overlies a well-settled mid and lower snowpack. Surface hoar and near-surface facets may be mingled within the upper few cm. Storm slab properties may change and become more cohesive as the alpine gets some sun and warmer temperatures. Wind slabs, found in the lee of ridges and ribs, are still reactive in some spots and healing in others.A weak layer which was buried in early December is down about 40-100 cm. At and below treeline, it mainly consists of large surface hoar. At higher elevations, it consists of a sun crust, facets, and/or small surface hoar. This layer is still reactive in some snowpack tests and has produced at least one human-triggered avalanche in the last week. The persistent slab is a low probability, high consequence problem. Below this layer, the snowpack is thought to be generally strong and well-settled.
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.