Avalanche Forecast

Issued: Mar 19th, 2018 4:56PM

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

Avalanche Canada cgarritty, Avalanche Canada

High north aspects continue to hold the best snow as well as a lingering storm slab problem.

Summary

Confidence

High -

Weather Forecast

Tuesday: Cloudy with scattered flurries bringing a trace to 5 cm of new snow, continuing overnight. Light to moderate southwest winds. Freezing level to 1500 metres with alpine high temperatures around -5.Wednesday: Cloudy with continuing scattered flurries and a trace to 5 cm of new snow, continuing overnight. Light southeast winds, increasing overnight. Freezing level to 1500 metres with alpine high temperatures around -5.Thursday: Cloudy with scattered flurries bringing about 3 cm of new snow, increasing overnight. Strong southeast winds. Freezing level to 1700 metres with alpine high temperatures of -2.

Avalanche Summary

Reports from Sunday included two small skier-triggered storm slabs that released on a north aspect in the alpine. Their crown fractures were 25 cm deep.Last Wednesday there were reports of several natural, loose, wet avalanches up to size 1.5 on south aspects at all elevations, as well as a skier triggered wind slab (size 1) on a northeast aspect at 2300 m.

Snowpack Summary

Recent light snowfalls have been followed by warm daytime temperatures and glimpses of sun, setting up a couple of thin storm snow layers over temperature and sun crusts at lower elevations and on south aspects. On shaded aspects at higher elevations, these snowfalls have buried and preserved a couple of surface hoar layers now found up to 25 cm deep. New snow amounts taper with elevation and below 1800 m, minimal accumulations have buried a supportive crust on all aspects. This crust will likely break down with daytime warming, becoming moist in the afternoon. Persistent weak layers from early January and mid-December are still being reported by local operators. They are generally considered dormant, but could wake up with a surface avalanche stepping down, a large cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets.

Problems

Storm Slabs

An icon showing Storm Slabs
Isolated pockets of surface hoar on sheltered, high north aspects have let to prolonged reactivity of storm slabs about 25 cm deep.
Be cautious around steep or convex slopes where buried surface hoar may be preserved.Use extra caution in the afternoon if the snow becomes moist or wet.Give cornices a wide berth when travelling on or below ridges.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 20th, 2018 2:00PM

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