Avalanche Forecast

Issued: Apr 10th, 2017 3:28PM

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

mgrist, Avalanche Canada

Northwest Coastal.

Cornices remain the primary concern. Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.

Summary

Confidence

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

Weather Forecast

Unsettled weather and cool temperatures continue throughout the forecast period.TUESDAY: Cloudy with scattered flurries (5-10cm). Light southeast ridgetop winds. Freezing level around 1200 m.WEDNESDAY: Mix of sun and cloud with isolated flurries (0-5cm). Strong easterly ridgetop winds. Freezing level around 1500 m.THURSDAY: Mainly cloudy with isolated flurries (2-5cm). Moderate southeasterly ridgetop winds. Freezing level around 1400 m.

Avalanche Summary

On Sunday, several Size 2 wet slabs were triggered with explosives control work in the north of the region. Loose wet avalanches to Size 2 were also reported running naturally on solar (south facing) aspects.

Snowpack Summary

Small amounts of new snow (up to 10cm) fell in the past few days with light to moderate southerly winds. The new snow will likely be sitting on hard surfaces created by strong winds last week, or melt-freeze crusts below 1400m.Sunny breaks and warmer temperatures on Monday has likely left a supportive temperature crust on all aspects up to treeline. North facing alpine slopes reportedly have up to 10cm dry powder, on a firm crust. A weak layer of facets and crusts from late February are buried 100-120 cm down. The layer has been unreactive recently and has a variable distribution. That said, rapid warming of the snowpack or a large trigger, such as a cornice, may still have the potential to trigger it.

Problems

Cornices

Large cornices may become weak with daytime warming and have the potential to trigger slabs on the slopes below.

Give cornices a wide berth when traveling on ridges.Avoid steep slopes below cornices.Even small cornice falls may trigger larger avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Small amounts of new snow and moderate southerly winds may have formed thin wind slabs in lee features below ridgetops.

Avoid freshly wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.Approach steep lee and cross-loaded slopes with caution.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 11th, 2017 2:00PM