Avalanche Forecast

Issued: Feb 21st, 2019 4:31PM

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

mconlan, Avalanche Canada

Northwest Coastal.

The danger is based on 40 cm of snow that is forecast Thursday night. If you find lesser amounts, conservative route-selection is still recommended, as the new snow may not bond well to underlying layers and it may be touchy to human traffic.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

THURSDAY NIGHT: Cloudy with snowfall, accumulation 30 to 40 cm, moderate to strong southwest wind, alpine temperature -6 C, freezing level 500 m.FRIDAY: Cloudy with snowfall, accumulation 5 to 10 cm, light to moderate southwest wind, alpine temperature -5 C, freezing level 700 m.SATURDAY: Early-morning snowfall and clearing over the day, accumulation 5 cm, light east wind, alpine temperature -10 C.SUNDAY: Clear skies, light to moderate east wind, alpine temperature -12 C.

Avalanche Summary

On Wednesday, a few small (size 1.5) wind slab avalanches were triggered by skiers. The slabs were about 20 cm deep. Avalanche activity will likely increase Thursday night into Friday as the storm passes.

Snowpack Summary

The next storm on Thursday night and Friday will add to the recent 15 cm of snow from Tuesday. Around 30 to 40 cm of snow is expected with this storm, and it is falling with strong southwest wind. All of this snow overlies weak faceted snow that may sit above hard surfaces, like wind-pressed snow or a crust.In the south of the region, the remainder of the snowpack is well-settled.Around Bear Pass and in the north of the region, you may find two weak layers of surface hoar buried between 50 and 100 cm. The base of the snowpack may also be composed of weak and sugary faceted snow.

Problems

Storm Slabs

Upwards of 40 cm of snow is expected by Friday. This snow will likely form touchy slabs that may not bond well to underlying layers. The deepest deposits will be in lee and cross-loaded terrain, as the snow will fall with strong southwest wind.

Best to avoid avalanche terrain if you find 40 cm or more of accumulation.Be careful around wind-loaded pockets near ridge crests and roll-overs.Observe for the bond of the new snow with the underlying layers before entering avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Feb 22nd, 2019 2:00PM