Avalanche Forecast

High - The number, quality, or consistency of field observations is good, and supports our confidence.

SUNDAY NIGHT: Mostly clear. No new snow expected. Light southwest wind trending to strong at higher elevations. Treeline high around -7 C. Freezing level at valley bottom, with a possible temperature inversion pushing the temperature above 2000 m warmer than -5 C.

MONDAY: Mostly clear, with increasing cloud through the day. Possible trace of snow expected. Moderate southwest winds trending to strong at higher elevations. Freezing level rising to around 250-500 m. 

TUESDAY: Mostly cloudy. 5-10 cm of snow expected overnight, with another 5-12 cm through the day. Moderate to strong southwest wind trending to extreme at higher elevations. Possibly above 100 km/h. Freezing level rising to around 800 m.

WEDNESDAY: Overcast. 10-20 cm of snow expected overnight, with another 15-30 cm through the day. Moderate south wind trending to extreme southwest at higher elevations. Freezing level rising to around 1300m.

On Saturday, isolated size 1.5 to 2.5 natural and skier triggered windslab avalanches were reported around treeline on various aspects across the region.

On Friday, several natural and rider triggered storm slab avalanches up to size 2 were reported by professional operations in the region. Avalanche control with explosives produced size 2.5 to 3.5 avalanches, mostly in the storm snow. Also see this Mountain Information Network report for reports of avalanches during the storm on Friday in a busy, local Revelstoke touring zone.

The persistent early December crust/facet layer has recently been active in this region. A very large storm slab avalanche (size 3) ran naturally in Mount Revelstoke National Park on Friday afternoon. Up to 3 m of snow buried the highway. This avalanche path rarely affects the road (only once every 5 or 10 years). The avalanche appears to have been caused by a storm slab that stepped down to a deeper, persistent layer.

Also on Friday, a professional operation west of Revelstoke reported a large natural avalanche on this persistent layer in a northwest facing feature at treeline.

The region received 40 to 50 cm low-density snow and significant periods of strong southerly wind since the start of the storm Thursday. This snow few on a variety of surfaces, thin sun crust on solar aspects, isolated surface hoar at treeline on sheltered slopes, fresh wind slabs in lee alpine features at treeline and above or even previous storm snow (20-60 cm) from the last weekend's storm.

We're actively monitoring the early December crust. In some places, it's scoured and on the surface, while in wind-loaded terrain features it can be found as deep as 150 cm below the surface. It consists of faceted grains above a bulletproof crust formed by the Atmospheric Rivers of early December. There has been isolated avalanche activity on this crust in the last week that seems to be confined to complex alpine terrain. 

• If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
• Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.