Avalanche Forecast

Thursday night: Cloudy with isolated flurries and a trace of new snow. Light northwest winds.

Friday: Cloudy with light flurries bringing up to 5 cm of new snow before increasing overnight. Light to moderate southwest winds. Alpine high temperatures around -7.

Saturday: Cloudy with continuing light flurries bringing up to 5 cm of new snow, up to 25 cm with the previous night's accumulations. Light north winds. Alpine high temperatures around -9.

Sunday: A mix of sun and cloud. Light west winds, becoming moderate or strong at ridgetop. Alpine high temperatures around -8.

Reports from Wednesday included several new avalanches triggered with ski cutting as well as explosives control. Storm slab and wind slab crown fracture depths from 5-50 cm reflected a mix of the depth range of our most recent snowfall, occasional entrainment of new snow to the depth of our new crust, as well as recent wind loading at higher elevations.

Since the weekend storm, there have been several reports of small wind slabs from human triggers, primarily on easterly aspects at upper elevations, in addition to several reports of dry loose avalanches. 

During the weekend storm, numerous size 2-3.5 avalanches released naturally in the storm snow. These avalanches primarily occurred on leeward aspects at treeline and alpine elevations. Below tree line, large wet loose avalanches ran naturally on Friday and into Saturday during the warm temperatures.

Over the past week, there have been a handful of notable natural avalanches breaking on more deeply buried weak layers. These were very large (size 3-4) avalanches releasing on slopes above 2200 m in the southeastern part of the region. Although the likelihood is decreasing, these avalanches are a reminder that a deeper instability may linger in shallow, rocky, alpine start zones where the snowpack transitions from thick to thin. Wind slab avalanches or cornice fall may have the potential to step-down to these layers. 

20-40 cm of snow from light snowfalls over the week now overlies older wind-affected snow at high elevations as well as a widespread melt-freeze or rain crust with an upper extent that varies from 1900 metres in some areas to mountaintop in others. The depth of new snow diminishes considerably at lower elevations. This snow has shown variable reactivity, with reports showing a mix of soft wind slabs around treeline, sluffing of low density snow in steep terrain, and poor bonding with the buried crust where it exists.

The mid and lower snowpack are generally well settled and strong, but contain two deeper weak layers that we have been tracking since the early part of the season. The late December surface hoar layer, buried 100 to 180 cm deep, is now suspected to be dormant and for the most part bridged over by the firm crust mentioned above. 

The facet/crust layer from November exists near the ground in the highest elevations of the region and may not be bridged by the crust in these areas. It remains a limited concern that is likely only able to be triggered with a large load, in high elevation, thin snowpack areas of the Selkirks and the southern half of the region.

• Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
• Seek out sheltered terrain where new snow hasn't been wind-affected.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.