Avalanche Forecast

Issued: Nov 27th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada shorton, Avalanche Canada

Email

Intense wind has likely reshaped the snowpack and created the potential for avalanches on slopes that have been wind-loaded.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations. Confidence is due to a stable weather pattern; little change is expected for several days.

Weather Forecast

Mild and windy conditions over the next few days, especially along the eastern side of the divide where Chinook conditions are expected. 

FRIDAY NIGHT: Some light flurries with trace amounts of new snow, 50-90 km/h wind from the southwest, alpine temperatures around -5 C.

SATURDAY: Clearing skies throughout the day, 30-60 km/h wind from the west, freezing level drops to valley bottom and alpine temperatures drop to -10 C.

SUNDAY: Clear skies, 30-50 km/h wind from the southwest, alpine high temperatures around -5 C.

MONDAY: Mix of sun and cloud, 40-70 km/h wind from the southwest, alpine high temperatures around -5 C.

Avalanche Summary

There have been a few reports of small (size 1) naturally triggered wind slab and loose dry avalanches in steep rocky terrain over the past few days. A few of them released near the ground, but were only 20-50 cm thick. Ongoing wind transport could form more wind slabs over the weekend, so be alert to slopes that have been wind affected.

Please submit your observations to the Mountain Information Network

Snowpack Summary

Strong wind over the weekend will continue to redistribute the 10-15 cm of snow that fell on Tuesday night. Snowpack depths are variable with reports of 50 to 100 cm in terrain that hasn't been scoured by the wind. There are some reports of a hard crust buried about 30 cm below the surface, which could be a bed surface for wind slab avalanches. There is most likely a crust at the bottom of the snowpack, and there have been a few reports suggesting weak snow may be forming around these crusts. This layer could become a bigger concern when it gets buried deeper.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.

Problems

Wind Slabs

An icon showing Wind Slabs

Surface snow will continue to blow around over the weekend and could form unstable slabs on steep open slopes.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 28th, 2020 4:00PM