Avalanche Canada ahanna, Avalanche Canada

Northwest Inland Avalanche Forecast

Jan 13th, 2020 4:00PM

If you're braving the cold on Tuesday, be on alert for wind slabs in lee features at all elevations and loose dry sluffing in steep, sheltered terrain.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Monday night: Clear. Moderate east to southeast winds. Alpine temperatures around -32.

Tuesday: Sunny. Moderate east to southeast winds. Alpine temperatures around -30.

Wednesday: Sunny. Moderate east to southeast winds, increasing to strong over the day. Alpine temperatures around -27.

Thursday: Sunny. Strong east to south winds, decreasing to moderate over the day. Alpine temperatures around -23.

Avalanche Summary

Reports from the Bulkley Valley Monday morning detail natural windslab and persistent slab avalanche activity, size 2.5-3 on aspects lee to ongoing strong outflow winds.

Looking forward, windslab avalanches will remain our primary concern. In sheltered areas, under forecast frigid temperatures unconsolidated snow may be reactive to human triggering as dry loose sluffs.

Snowpack Summary

Extensive wind effect observed at alpine and treeline. Scoured north to east aspects, hard wind slab in lees, with lots of snow sublimating into the air. Not much snow remains for wind transport by the forecast continued outflow. Snow in protected areas is unconsolidated and well preserved by the cold temperatures.

The surface snow may cover a layer of surface hoar at lower elevations in sheltered areas, or a thin sun crust on steeper south-facing slopes. A concerning pair of surface hoar layers are currently buried about 80-120 cm below the surface in sheltered areas around treeline. There is uncertainty about whether this layer remains a problem, but there have been no reports of avalanche activity associated with them for a few weeks, during which several storm slab avalanche cycles have tested their potential for step-downs.

Terrain and Travel

  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.

Valid until: Jan 14th, 2020 5:00PM