Avalanche Forecast

Issued: Dec 13th, 2019 4:00PM

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

Avalanche Canada MBender, Avalanche Canada

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Flurries have steadily accumulated new snow in the past 24 hours. This combined with moderate west winds have made wind slabs at upper elevations the primary concern.

Summary

Confidence

Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region.

Weather Forecast

FRIDAY NIGHT: Scattered flurries, 30 km/h wind from the west, alpine high temperatures around -4 C.

SATURDAY: Mostly cloudy, light wind from the northwest, alpine high temperatures around -6 C.

SUNDAY: Mix of sun and cloud, light wind from the northwest, alpine high temperatures around -8 C.

MONDAY: Mix of sun and cloud, light wind from the west, alpine high temperature -8 C.

Avalanche Summary

Recent avalanche activity has primarily been limited to small wind slab avalanches (size 1) triggered with explosives. On Thursday there was a report of a size 2.5 storm slab avalanche on a northeast aspect in the alpine, which scoured down to a crust near the base of the snowpack. 

Snowpack Summary

New snow and wind has formed fresh wind slabs at upper elevations. In sheltered areas 30-40 cm of snow from last weekend is gradually settling. Crust layers from November and October can be found 40-100 cm below the surface. These layers produced large avalanches with explosive triggers last weekend, but since then have appeared to gain strength. Large avalanches on these layers may still be possible to trigger in steep rocky terrain. Snowpack depths range between 50-100 cm at higher elevations and taper rapidly below treeline.

Problems

Wind Slabs

An icon showing Wind Slabs

Triggering wind slab avalanches is likely at higher elevations where the wind has blown fresh snow into reactive slabs.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

The likelihood of triggering a large avalanche on one of the crusts and weak layers in the lower snowpack is gradually reducing, but the consequence is high.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 14th, 2019 5:00PM