Avalanche Forecast

Issued: Feb 24th, 2018 4:54PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Loose Dry.

pgoddard, Avalanche Canada

Northwest Coastal.

Ongoing snow and wind are expected to cause a rise in avalanche activity.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

SATURDAY NIGHT: 15-20 cm snow. Strong west to south-westerly winds.SUNDAY: 5-10 cm snow. Freezing level near 400 m. Moderate to strong westerly winds. MONDAY: 5-10 cm snow during the day, with a further 15-20 cm overnight. Freezing level near 400 m. Strong south-westerly winds.TUESDAY: Around 10 cm snow. Freezing level near 400 m. Strong westerly winds.More details can be found in the Mountain Weather Forecast.

Avalanche Summary

The beginnings of a natural avalanche cycle were reported on Friday, with loose avalanches in steep terrain and wind slabs to size 2 failing naturally.Ongoing snow and wind are expected to cause a rise in avalanche activity throughout the weekend.

Snowpack Summary

Snow and wind over the weekend are building storm slabs and wind slabs in open terrain at alpine and treeline elevations. Storm snow is sluffing readily in steep terrain. New snow has buried old hard wind slabs, scoured surfaces and sastrugi in many exposed areas. In wind-sheltered terrain, sun crusts or dry facets sit below the recent storm snow.In the upper pack is an interface of sun crusts, facets and spotty surface hoar (which is most prevalent in sheltered treed locations). Deeper in the snowpack, around 50-150 cm down, you'll find a crust/surface hoar layer, which still has the chance to surprise you and could be triggered from a thin snowpack spot, or with a large trigger like cornice fall.

Problems

Storm Slabs

New snow and wind have built fresh slabs, which may fail naturally or with the weight of a person. A storm slab could step down to a deeper weak layer, creating a surprisingly large avalanche.

Use conservative route selection. Choose moderate angled and supported terrain with low consequence.Give cornices a wide berth when travelling on or below ridges.Be aware of what is above you at all times.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Dry

Dry new snow is likely to sluff easily in steep terrain, especially where it overlies a hard crust.

Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.If triggered, loose dry avalanches may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Feb 25th, 2018 2:00PM