Avalanche Forecast

Issued: Dec 4th, 2017 5:02PM

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

mgrist, Avalanche Canada

Sea To Sky.

Don't let your guard down with the sunny weather and fresh snow. Take a cautious approach towards more aggressive terrain - especially steep, wind-affected terrain.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're into a period of fine weather for the foreseeable future, with significant warming from Wednesday onwards. Tuesday: Mainly sunny and becoming warm up high. Freezing levels rising to 1500 m. Light northerly winds.Wednesday: Sunny. Light northerly winds. Freezing levels 3000m. Alpine high temperatures to +2 Celsius.Thursday: Sunny and warm. Freezing levels around 3500 m. Light northwesterly winds. Alpine high temperatures to +5 Celsius.

Avalanche Summary

On Sunday, a Size 1 storm slab was reported in the north of the region - on a steep, unsupported convex roll. Otherwise, no new avalanches observed.

Snowpack Summary

Approximately 40-60 cm of snow from late last week now sits on top of a rain crust (or multiple crusts) that formed during the wet weather at the end of November. Strong (southerly) winds have blown snow around in exposed areas creating drifts and scoured areas. For the most part, the riding in the region consists of 20-30cm of low density snow that is right-side up (the snow gets more dense as you go deeper into the snowpack). The main areas of concern are lee (down wind) north facing and cross-loaded features in the alpine and tree line elevation bands. Snowpack depths are typically around 150 cm in sheltered tree line locations, although deeper (and shallower) spots certainly exist on account of the strong winds.

Problems

Wind Slabs

Wind slabs have been building over a crust layer in specific, mostly north facing locations. This layer may slide easily, particularly on steep convex terrain or where the wind has blown it into more cohesive slabs.

Use ridges or ribs to avoid pockets of wind loaded snow.Avoid steep lee and cross-loaded featuresBe alert to changing snow conditions, especially where the snow firms up or sounds hollow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 5th, 2017 2:00PM