Avalanche Forecast

Issued: Nov 29th, 2019 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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Sunny and cold conditions in the forecast for the weekend. Watch for lingering pockets of wind slab around ridge tops and early season obstacles below treeline.

Summary

Confidence

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

Weather Forecast

Friday Night: Clear skies, moderate wind from the northeast, alpine temperatures -12 C.

Saturday: Mix of sun and cloud, light wind switching to SE, alpine high -8 C.

Sunday: Increasing cloud in the afternoon, moderate wind from the southwest, alpine high -8 C.

Monday: Cloudy with isolated flurries, wind increasing to strong from the southwest, alpine high -5 C. Freezing level 700 m.

Avalanche Summary

Ridge tops and slopes where previous wind has deposited blowing snow are places where avalanches could most likely be triggered right now. Early season avalanches can most easily propagate and run in areas where the underlying ground is smooth, such as on glaciers, rock slabs, scree, or grassy slopes.

Observations are limited this time of year, so there is a fair bit of uncertainty about the extent of current avalanche activity. If you see anything while out in the field, please consider sharing that information with us and fellow recreationists via the Mountain Information Network (MIN).

Snowpack Summary

Recent reports describe scoured windward aspects, hard wind slabs and variable snow depths due to wind transport in the alpine and treeline. Up to 50 cm overlies the rain crust at these elevations. Soft snow may still be found below treeline but the snow pack is quite thin at this elevation. Underneath the surface snow at higher elevations lies a lower snow pack largely characterized by sandwiches of crusts and large, weak snow crystals (facets), as observed in another recent MIN report. We're also keeping an eye on a potential surface hoar layer (see video here). With few field observations, uncertainty remains on the distribution and reactivity of these layers.

Problems

Wind Slabs

An icon showing Wind Slabs

While wind slab avalanches are becoming less likely, watch for small pockets in extreme terrain where consequences of a small avalanche could be high.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 1.5

Valid until: Nov 30th, 2019 5:00PM