Avalanche Forecast

Issued: Dec 11th, 2019 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

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Human triggered slab avalanches are possible on slopes loaded by new snow and wind.

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

WEDNESDAY NIGHT: 10-20 cm of snow, 60 km/h wind from the south, alpine temperatures drop to -6 C.

THURSDAY: 5-10 cm of new snow, 40 km/h wind from the southwest, alpine high temperatures around -4 C.

FRIDAY: Another 10-15 cm of new snow by midday then clearing in the afternoon, 30 km/h wind from the southwest, alpine high temperatures around -4 C.

SATURDAY: Mix of sun and cloud, light wind, alpine high temperatures around -6 C. 

Avalanche Summary

No recent avalanches have been reported. Looking ahead, the main concern is new slabs forming above the surface hoar crystals that current sit on top of the snowpack. Over the next few days the likelihood of triggering storm slab or wind slab avalanches will increase as snow accumulates above this layer.

Snowpack Summary

Incoming stormy weather will bury a concerning layer of surface hoar that has formed in areas sheltered from the wind. As snow accumulates above this layer expect to find very reactive slabs. Reports suggest this layer can be found on all aspects up to treeline elevations. In the alpine, the new snow will bury hard wind slabs and sun crusts on south-facing terrain. The lower snowpack is generally considered strong and settled, as there has been very little to report in terms of recent avalanche activity or snowpack test results on deeper layers. Snowpack depths at treeline likely range from 90-160 cm and taper quickly at lower elevations.

Problems

Wind Slabs

An icon showing Wind Slabs

Expect new snow and wind to form fresh wind slabs over the next few days. Even thin wind slabs could be very reactive and propagate widely because the new snow is burying large surface hoar crystals.

Aspects: North, North East, East, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 12th, 2019 4:00PM