Incoming weather systems will have a variable effect across the region. See 'forecast details' for more.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
In general, the weekend’s storm is forecast to hit the northern part of the region (near Revelstoke) most heavily, with progressively less snow as you go south. Freezing levels will climb the highest in the south. Weather will be very variable across the region, so avalanche danger will correspondingly be variable.Saturday: Moderate snow (~15-35cm), with highest amounts in the north and west. Freezing level gradually rising to around 1500m. Strong westerly winds.Sunday: Freezing level continuing to rise, peaking at about 1700m. Moderate precipitation (~15-35mm), with highest amounts in the north and west. Strong westerly winds.Monday: A cold front brings moderate to heavy precipitation with the freezing level dropping to valley bottom overnight as the front departs.
Avalanche Summary
Many avalanches have been triggered remotely (from several hundred metres away) and accidentally by skiers and machinery this week. These avalanches are failing on upper snowpack persistent and storm snow weaknesses, on almost all aspects and elevations. Natural avalanche activity is likely to increase again this weekend with incoming weather.
Snowpack Summary
Snow is falling with strengthening winds and rising temperatures, creating a nice recipe for new storm slab and wind slab instabilities. Widespread persistent weak layers buried in February, which have remained touchy and unpredictable all week, are a key concern at all elevations. Storm slabs, sluffs or a person could easily trigger these deeper weaknesses. Avalanches may be larger than you expect, given the amount of fresh snow. Large cornices also loom as potential triggers for deep avalanches.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.