Avalanche Forecast

Issued: Apr 1st, 2018 4:18PM

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

Avalanche Canada mconlan, Avalanche Canada

New and old slabs are taking their time to bond to underlying layers. Be cautious on southerly aspects when the sun is out -- it could weaken the snow and trigger avalanches.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

MONDAY: Partly cloudy, light southerly winds, alpine temperature -12 C, freezing level 400 m.TUESDAY: Mostly cloudy with light snowfall, accumulation 2 to 5 cm, light to moderate southerly winds, alpine temperature -11 C, freezing level 500 m.WEDNESDAY: Mostly cloudy with light snowfall, accumulation 1 to 3 cm, light southerly winds, alpine temperature -10 C, freezing level 500 m.

Avalanche Summary

On Saturday, a large persistent slab avalanche was reported in the north of the region, failing on the early-March weak layer described in the Snowpack Discussion.  It failed on an easterly aspect around treeline.  Portions of the avalanche stepped down to sugary facets near the bottom of the snowpack.Otherwise, there was further evidence of the natural cycle that occurred on Friday within the recent storm snow, with storm slab and loose dry avalanches.  They were small to large (size 1 to 2.5), on all aspects, and at all elevations.

Snowpack Summary

Expect to find a surface crust on southerly aspects from the weekend’s clear skies.A reactive slab about 50 cm thick has developed from last week’s storm snow.  This slab overlies two layers of weak surface hoar, which exist on shaded aspects at high elevations.  The slab sits on a melt-freeze crust on all aspects below treeline.  The storm snow may still be loose in sheltered and shady locations.Near the bottom of the snowpack, weak and sugary facets are found in shallow, rocky snowpack areas.  Storm slabs have stepped down to these facets recently, producing very large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs
Recent storm slabs are found in the south of the region and older slabs exist in the north.  Very large avalanches have occurred, as the snow is not bonding well to underlying layers of surface hoar, crusts, or sugary facets in thin snowpack areas.
Use caution above cliffs and terrain traps where small avalanches may have severe consequences.Observe for signs of instability, such as cracking, whumpfing, and avalanche activity.Approach lee and cross-loaded slopes with caution.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Apr 2nd, 2018 2:00PM

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