Avalanche Forecast

Issued: Feb 22nd, 2018 4:15PM

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

Avalanche Canada mconlan, Avalanche Canada

New snowfall may not bond well to underlying snow surfaces. Expect old and new wind slabs on all aspects at higher elevations, loose dry snow in sheltered areas, and looming cornices on ridgelines.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

FRIDAY: Cloudy with snowfall, accumulation 5 to 15 cm, strong southwesterly winds, alpine temperature -12 C, freezing level below valley bottom.SATURDAY: Cloudy with early-morning snowfall then clearing to mostly sunny, light northwesterly winds, alpine temperature -12 C, freezing level near 600 m.SUNDAY: Cloudy with early-morning snowfall, accumulation 10-15 cm, moderate to strong westerly winds, alpine temperature -13 C, freezing level near 600 m.

Avalanche Summary

Cornices were explosively controlled on Wednesday, producing small to large releases (size 1 to 2.5). Expect natural and human-triggered avalanche activity to increase with the incoming storms.

Snowpack Summary

New storm snow will fall on highly variable and wind-affected snow surfaces. In exposed terrain, new snow will fall on scoured north facing slopes and wind-loaded south facing slopes. In sheltered terrain, new snow will fall on last weekends storm snow. The new snow may not bond well to these surfaces and could be reactive to both natural and human triggers.Deeper in the snowpack, a crust layer can be found on sun-exposed slopes below 1900 m, which allowed for slab avalanches to propagate widely over the past week.Even deeper, avalanche professionals are still monitoring the mid-January crust. This layer is now 150-200 cm deep, but a heavy trigger (such as a cornice fall) or the next major storm (loading and/or warming) could wake this layer up.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow with strong southwesterly wind will produce fresh wind slabs in lee features. These sit on wind slabs formed during last weekends storm. Watch for signs of avalanche activity and locally unstable snow.
Sheltered slopes at lower elevations will offer the best riding.Use ridges or ribs to avoid pockets of wind-loaded snow.Approach lee and cross-loaded slopes with caution.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Feb 23rd, 2018 2:00PM