Avalanche Forecast

Issued: Feb 22nd, 2018 4:00PM

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.

Weather forecast models disagree about snow amounts. If it is snowing heavily and/or blowing in your area, expect high avalanche danger.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

THUSRDAY NIGHT/ FRIDAY: 20-40 cm light dry snow. Freezing level near 600 m. Moderate south-westerly winds. Weather models suggest heaviest snow in the Terrace area, with less as you travel east and north.SATURDAY: 5-10 cm snow. Freezing level near 400 m. Moderate south-westerly winds. SUNDAY: 10-20 cm snow. Freezing level near 400 m. Light to moderate south-westerly winds. More details can be found in the Mountain Weather Forecast.

Avalanche Summary

Rapid wind loading caused a natural avalanche cycle on Wednesday. On steep solar aspects, size 1-2 loose wet avalanches were also observed.New snow and wind are expected to cause a rise in avalanche activity on Friday and the weekend.

Snowpack Summary

Incoming snow is expected to be light and dry, but will come with moderate to strong south-westerly winds. Loose snow sluffing and fresh wind slabs are likely problems on Friday. New snow will overlie old soft and hard wind slabs. 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 are building 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.Minimize overhead exposure during periods of heavy loading from new snow or wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

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 23rd, 2018 2:00PM