A touchy persistent slab problem demands respect. Use extra caution in your terrain selection.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A few flurries are possible on Wednesday ahead of a couple of Pacific storms on Thursday and Friday. 5-15 cm of snow is expected each day, with moderate to strong SW winds. The freezing level rises to around 1500 m on Thursday.For more details check out https://avalanche.ca/weather.
Avalanche Summary
Avalanche activity has been widespread over the last few days as recent snow has reached a critical load above a volatile weak layer. Human and naturally-triggered avalanches have been most prevalent below treeline, but have also occurred at higher elevations in some parts of the region. These have mostly been in the size 1-2 range, with many triggered remotely from a distance. Wind slabs have also been reported in wind-exposed terrain.
Snowpack Summary
A 40-80 cm persistent slab overlies a variety of surfaces including large surface hoar, sun crusts, and facets. This slab is ripe for human triggers and is especially touchy below treeline. Recently formed wind slabs also exist on lee features at alpine and treeline elevations. The mid and lower snowpack are generally well settled and strong.
Problems
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.
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.