Avalanche Forecast

Issued: Dec 5th, 2017 4:23PM

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

Avalanche Canada shorton, Avalanche Canada

Soaring alpine temperatures will test the snowpack this week. Be extra cautious around sun exposed slopes.

Summary

Confidence

Low - Due to the number and quality of field observations

Weather Forecast

WEDNESDAY: Sunny with valley cloud in the morning, light northwest wind, inversion forming with alpine temperatures possibly reaching above 0 C.THURSDAY: Sunny with valley cloud, light wind, inversion with freezing level up to 3000 m.FRIDAY: Sunny with valley cloud, light wind, inversion with freezing level up to 2700 m.

Avalanche Summary

No recent avalanches have been reported. On the weekend, small loose dry avalanches were reported in steep terrain around Valemount and Blue River, but no human-triggered avalanches were reported. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

The snowpack is about to experience a big change with a week of warm sunny weather ahead. Widespread melting is expected, with the most intense warming on steep south-facing slopes. Warming could potentially impact deeper layers including a combination of crusts that formed during rain events in November. Little is known about the depth, distribution, or reactivity of these crusts. Wind slabs formed at higher elevations over the past week and will likely continue to be reactive. Snow depths decrease rapidly below treeline, where the primary hazards are rocks, stumps, and open creeks.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs will become touchy as the snow warms up, especially on steep south-facing slopes. Also watch for wind-loaded slopes on ridges and gullies.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
Not much is known about buried crusts lurking in the snowpack, but dramatic warming could potentially awaken deep weaknesses in the snowpack. Uncertainty about these layers warrants conservative terrain selection.
Minimize exposure to steep slopes on warm or sunny days.Use extra caution on slopes if the snow is moist or wet.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 6th, 2017 2:00PM