Avalanche Forecast

Issued: Dec 5th, 2017 4:55PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet and 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. 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.Friday: Sunny and warm. Freezing levels around 3400 m. Light northerly winds.

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. The snow appears to be bonding well to the crust with no avalanche activity reported recently on this layer.Up high, the main concern has been winds (first from the south, and more recently from the north) that have blown snow around in exposed areas creating drifts and scoured areas. The take-home message is that wind slabs can be found on many aspects at higher elevations - including some southerly aspects, which is an unusual pattern. Other than steep south facing slopes, much of 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).

Problems

Loose Wet

Conditions will be more like spring than winter this week. Surface snow layers can become weak when hit by the sun. Minimize your exposure to terrain traps - even small sluffs can push you into dangerous terrain.

Use extra caution on sunny slopes or if the snow is moist or wet.Use caution above cliffs and terrain traps, where small avalanches may have severe consequences.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

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.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

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