Avalanche Forecast

Issued: Feb 23rd, 2017 3:55PM

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

Avalanche Canada cgarritty, Avalanche Canada

Forecast models are showing uncertainty about snowfall on Friday morning. Friday's danger ratings are currently based on receiving about 10cm of new snow.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

Friday: Cloudy with flurries bringing a possible 5-10 cm of new snow. Winds light from the southeast. Freezing level to 700 metres with alpine temperatures of -2. Saturday: Mainly cloudy with scattered flurries bringing up to 5 cm of new snow, beginning in the afternoon. Winds light to moderate from the west. Freezing level to 500 metres with alpine temperatures of -2. Sunday: A mix of sun and cloud with isolated flurries and a trace of new snow. Winds light from the northeast. Freezing level to 800 metres with alpine temperatures of -1.

Avalanche Summary

No new slab avalanches have been reported recently but the thin graupel layer that exists on the surface in some areas has been noted sluffing fast over long distances. Forecast accumulations of new snow can be expected to increase this hazard.Although the extent of recent wind slab formation is uncertain, the possibility for lingering wind slabs remains a concern. Look for these in immediate lee features on northerly aspects in exposed, high elevation terrain.

Snowpack Summary

Scattered convective flurries recently deposited up to 3cm of graupel on the snow surface in some areas of the South Coast. Below it, the snow surface is a mix of sun crust on solar aspects and surface hoar on shaded aspects. At higher elevations, the widespread mid-February rain crust is now down around 30-50 cm, below our recent storm snow. This recent snow is reportedly well bonded to the crust. The crust itself is supportive and roughly 20cm thick. Below the crust, the snowpack is still moist as a result of the heavy rain from last week. Moderate southerly wind during the storm may have formed wind slabs at ridge crests.

Problems

Storm Slabs

An icon showing Storm Slabs
Any new snow accumulations we receive by Friday morning are expected to form a poor bond to the current snow surface. This may result the formation of touchy new storm slabs or, if the snow is less cohesive, a loose dry avalanche problem.
Be cautious of sluffing in steep terrain.Use caution in lee areas in the alpine and treeline. Storm snow may form touchy slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 24th, 2017 2:00PM