Archived

Avalanche Forecast

Mar 4th, 2018–Mar 5th, 2018

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Sea To Sky.

A week of benign weather will allow the snow to gain strength, but you should remain wary of solar aspects where new snow rests on a buried sun crust that may remain sensitive to human triggering.

Confidence

Moderate -

Weather Forecast

MONDAY: Mostly cloudy with isolated flurries and a trace of new snow, light west wind, freezing level rising to around 700 m.TUESDAY: Mix of sun and cloud, light wind, freezing level rising to around 1000 m.WEDNESDAY: Sunny, light wind, freezing level rising to around 1300 m.

Avalanche Summary

On Saturday, a few natural size 1-2 slabs were reported on north aspects and numerous wet loose avalanches were reported on steep south-facing terrain. Several small snowmobile triggered avalanches (size 1) were reported at treeline elevations in the Brandywine area.On Friday, a few human triggered avalanches up to size 2.5 were reported. A size 1.5 and second size 2.5 were triggered on southwest facing slopes between 1900 and 2000 m. These likely failed on the February 22nd interface, which presents as a crust with surface hoar and/or facets on it. South facing slopes may be where this interface is most reactive. A skier also remotely triggered a size 1.5 avalanche on a wind loaded slope of unknown aspect/elevation.

Snowpack Summary

A thin sun crust has formed on solar aspects and the surface is wind affected in most exposed terrain. 40 cm of storm snow from last week is gradually settling and may be sitting on a thin layer of surface hoar in sheltered areas.The February 22nd interface is now 50 to 70 cm below the surface. This layer is composed of old wind slabs, spotty surface hoar, facets and a sun crust on solar aspects. Snowpack testing suggests this layer may remain reactive, particulary on south-facing slopes. The snowpack is well settled and stronge beneath the February 22nd interface. Variable winds in the past month have produced cornices on many ridgelines. They will become touchier as they grow in size, as temperatures rise, and when they are subject to the strong late-winter sun on clear days.

Avalanche Problems

Storm Slabs

20 to 45 cm of recent snowfall arrived with strong wind. This slab is gaining strength and settling out quickly, but you should remain wary of south facing slopes where the new snow sits on a buried sun crust that is not worthy of your trust.

Start with simple terrain and slowly step out as you gather information about the new snow.Caution with south facing slopes, brief periods of sun could initiate avalanche activity.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Cornices

Continued snowfall and strong wind from around the clock has formed large cornices on many ridgelines. Cornices are inherently unstable, unpredictable, and demand respect, especially when the sun is out.

Give cornices a wide berth when traveling on or below ridges.Firm cornices may pull back into flat terrain at ridgetop if they fail.

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1.5 - 3