Avalanche Forecast

Issued: Jan 5th, 2019 4:25PM

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

Avalanche Canada mbender, Avalanche Canada

Caution as you transition into wind exposed terrain, wind blowing from a variety of directions have developed wind slabs on a variety of aspects.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

SATURDAY NIGHT: Cloudy with isolated flurries, light east winds, alpine temperature -6 CSUNDAY: Cloudy with flurries, accumulation up to 5 cm, light east winds, alpine temperature -5 CMONDAY: Mix of sun and cloud, light to moderate southwest winds, alpine temperature -9 CTUESDAY: Mix of sun and cloud, light east winds, alpine temperature -10

Avalanche Summary

There have not been any recent reports of avalanche activity in the south of the region. Reports from Ningunsaw in the far north of the region on Friday, show explosives controlled avalanches running to size 2.5 with evidence of a previous natural avalanche cycle that was suspected to have happened during the storm earlier in the week. These avalanches were suspected to run on a weak layer of feathery surface hoar buried in late December and some were reported to have failed to the ground.

Snowpack Summary

Strong and variable winds have produced variable surfaces at treeline and alpine elevations. Expect to find wind-scoured surfaces as well as wind slabs in lee terrain features. Below treeline, expect to find a melt-freeze crust near the snow surface.Buried under recent storm snow, you may find a few weak layers in sheltered areas comprising of feathery surface hoar crystals and/or sugary faceted snow. The upper layer was buried around December 31 and is about 20 cm deep. The next layer may have been buried around December 22 and is likely 30-50 cm deep. The lower one was buried in early-December and is now approximately 80-120 cm deep. The bottom 30 to 50 cm of the snowpack consists of weak and sugary faceted grains and crusts, particularly in areas where the snowpack is thin. It is possible that shallower avalanches could scrub down to ground in these thin snowpack areas, due to this weak layer at the base of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Strong winds have affected treeline and alpine terrain. Wind slabs may linger in the lee sides of terrain features. Should one be triggered, it is possible that it may scour to the ground, particularly in thin snowpack areas.
If triggered, wind slabs may step down to deeper layers resulting in large avalanches.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Be careful with wind-loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Jan 6th, 2019 2:00PM