Avalanche Canada ahanna, Avalanche Canada

Northwest Inland Avalanche Forecast

Jan 14th, 2020 4:00PM

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

It is dangerously cold out there right now. Save your toes for more tolerable temperatures this weekend.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Tuesday night: Clear. Moderate east winds. Alpine temperatures around -34 C.

Wednesday: Sunny. Moderate east winds, increasing to strong outflows over the day. Alpine temperatures around -32 C.

Thursday: Mix of sun and cloud. Strong east to southeast winds, decreasing to moderate over the day. Alpine temperatures around -28 C.

Friday: Mix of sun and cloud. Light to moderate southeast to southwest winds. Alpine temperatures around -24 C.

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 previous strong outflow winds. The persistent slab avalanches are suspected to be isolated incidents of avalanches running on the deep November crust.

Looking forward, windslabs will likely become less reactive as they lose cohesion in the cold temperatures. In sheltered areas, unconsolidated snow may be reactive to human triggering as dry loose sluffs.

Snowpack Summary

North to east aspects in the alpine have been wind scoured, with isolated hard windslab in lees. Wind effect also observed in open areas at treeline and below, while snow in protected areas is unconsolidated and well preserved by the cold temperatures.

A pair of surface hoar layers are currently buried about 80-120 cm below the surface in sheltered areas around treeline. 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.

A deep crust from mid November lies at the base of the snowpack. Although this has not been an active avalanche problem, a couple of recent large avalanches are suspected to have run on this layer in isolated incidents high in the alpine.

Terrain and Travel

  • Avoid terrain traps where the consequence of any avalanche could be serious.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 2

Recent strong outflow winds have blown snow into wind slabs extensively in the alpine and in open areas at treeline and below. They will likely become less reactive as they lose cohesion in the cold temperatures.

Aspects:

South East, South, South West, West, North West.

Elevations:

All elevations.

Valid until: Jan 15th, 2020 5:00PM