Avalanche Forecast

Moderate

In the Pine Pass area, heavy snowfall caused a natural avalanche cycle that started on Thursday and continued through the weekend. Reports from Thursday indicate storm slabs were very reactive to snowmobile traffic, producing many size 1 to 1.5 storm slab avalanches that propagated widely.

On Saturday, explosives control produced several size 2 to 3 wind slab avalanches in cross-loaded alpine start zones.

On Sunday, three very large natural avalanches were observed up to size 4. Two were size 3 persistent slab avalanches on steep north-facing aspects with 750 m crowns. A size 3.5-4 deep persistent slab avalanche was also observed. It is suspected this avalanche failed in depth hoar at the base of the snowpack.

See more on the potential of triggering deeper weak layers in our latest Forecasters' Blog.

Stormy weather over the past week has brought 50 to 100 cm of new snow to the region. Warm windy weather is causing storm snow to settle into reactive slabs. The storm snow sits on previously wind-affected surfaces. Below this, a melt-freeze crust is found on sun-exposed slopes and everywhere below 1600 m.

Several crust/facet/surface hoar layers exist in the upper and middle portions of the snowpack. The most concerning persistent weak layer is at the base of the snowpack from large and weak facets formed in November. This layer is widespread and most likely problematic in steep, rocky alpine and upper treeline terrain.

Monday Night 

Cloudy with scattered flurries, 8-15 cm accumulation. Localized areas, particularly around Kakwa, may see higher accumulations with up to 25 cm. Alpine temperatures low of -3 C. Ridge wind southwest 60 km/h, 70-80 km/h over Kakwa. Freezing level slowly lower to 1000 m overnight. 

Tuesday 

Mix of sun and cloud with isolated flurries, 2-5 cm accumulation. Alpine temperatures drop to -6 C. Ridge wind southwest 40-60 km/h. Freezing level 1200 meters. 

Wednesday 

Mainly cloudy with sunny periods and isolated flurries, 2-5 cm accumulation. Alpine temperatures rise to -7 C. Ridge wind southwest 60 km/h easing in the afternoon. Freezing level 1000 meters. 

Thursday 

Mainly sunny with cloud increasing in the afternoon and isolated flurries, 2-10 cm accumulation. Alpine temperatures rise to -3 C. Moderate ridge wind from the southwest picks up to 50-70 km/h in the evening. Freezing level 1500 meters. 

More details can be found in the Mountain Weather Forecast.

• Keep your guard up at lower elevations. Storms slabs have been reactive at all elevations.
• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
• If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.