Avalanche Forecast

Issued: Feb 14th, 2019 4:16PM

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

Avalanche Canada shorton, Avalanche Canada

Upper elevations are heavily wind affected, watch for wind slabs in steep terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

THURSDAY NIGHT: 5-15 cm of snow, moderate southeast wind, alpine temperatures drop to -10 C.FRIDAY: Isolated flurries with trace accumulations, light south wind, alpine high temperatures around -6 C.SATURDAY: Cloudy then clearing later in the day, light wind, alpine high temperatures around -6 C.SUNDAY: Mix of sun and cloud, light wind, alpine high temperatures around -8 C.

Avalanche Summary

On Thursday, skier traffic produced small (size 1) wind slabs near ridges and some minor sluffing in steep terrain.Similar avalanche activity was reported over the past few days. On Wednesday, a size 1.5 slab avalanche was observed on a steep southwest-facing line in the Whistler/Blackcomb backcountry (see this MIN report). On Tuesday night, a widespread cycle of small (size 1) loose dry avalanches occurred. Over the weekend, small pockets of wind slab were reactive to skier traffic in steep and immediate lee features. Of note is a MIN from the Whistler backcountry reporting wind slabs at lower elevations and in more sheltered terrain than usual (see the MIN here).

Snowpack Summary

Areas around Squamish could see up to 20 cm of new snow by Friday afternoon, while much less is expected further north. Recent wind has scoured and redistributed the snow from earlier this week into fresh wind slabs in lee terrain. Sheltered areas may still have 10 to 30 cm of low density snow. Due to the scouring and wind-loading, anywhere from 0-100 cm of snow sits on a crust on all aspects below 2000 m and solar aspects into the alpine. Above 1800 m, recent cold temperatures have been working to facet and break down the crust. In sheltered terrain at and below treeline, a layer of weak feathery surface hoar or sugary facets may be identified, but this interface has produced little recent avalanche activity. The remainder of the snowpack is generally well-settled.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent wind with moderate snowfall has formed wind slabs on a variety of aspects. Surface snow may also be sensitive to human triggering on south-facing features where it overlies a crust.
Minimize exposure to steep planar south-facing slopes.Watch for whumpfing, hollow sounds, and shooting cracks.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 15th, 2019 2:00PM

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