Avalanche Forecast

Issued: Dec 1st, 2021 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

Email

Wind slabs may be reactive on a variety of aspects at alpine and treeline elevations due to shifting winds. 

Summary

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

Wednesday night: Flurries up to 5 cm. Strong southwest wind. Alpine temperature around -12 C.

Thursday: Flurries up to 5 cm. Moderate southwest wind. Alpine temperature around -15 C.

Friday: Mix of sun and cloud with isolated flurries. Light southerly wind. Alpine temperature around -18 C. 

Saturday: Mix of sun and cloud. Light to moderate southwest wind. Alpine temperature around -14 C.

Avalanche Summary

No recent reports of avalanche activity. Over the weekend, large natural avalanches (size 2 and 2.5) were on alpine lee features. A MIN report also noted a slab release size 2 above Bryant Lake.

Lots of whumpfing and cracking have been notified across the region and are most likely to be associated with early-season shallow snowpack and wind-affected snow.

We were delighted to receive so many submissions to the Mountain Information Network last weekend! Keep it up! ?

Snowpack Summary

Incremental inputs of new snow continue to feed wind slab formation. Surface snow is wind affected on most aspects above the treeline. Whumfing and cracking has been observed where wind slabs sit on top of a weak, faceted lower snowpack which may also contain a crust layer.

Snow depths are approximately 80 cm at treeline and 100-120 in the alpine.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Wind slabs are most reactive during their formation.
  • Approach lee and cross-loaded slopes with caution.
  • 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

Changing winds and light snowfall amounts may form touchy wind slabs on all aspects above treeline. Cracking and whumfing in the upper snowpack are indicators of wind slab. Human triggering is possible. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 2nd, 2021 4:00PM