Avalanche Forecast

Issued: Mar 8th, 2022 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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Check your line for isolated pockets of wind slab in the alpine and be mindful of your sluff in steep terrain.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

Tuesday night: Partly cloudy. Light northeast wind. Alpine low around -18 °C.

Wednesday: A mix of sun and cloud. Light northwest wind. Alpine high around -12 °C.

Thursday: A mix of sun and cloud. Moderate northwest wind. Alpine high around -8 °C.

Friday: Overnight flurries bringing a trace of snow then clearing to a mix of sun and cloud. Moderate southwest wind. Alpine high around -3 °C. Freezing level rising to 1500 m.

Avalanche Summary

On Monday, ski cuts produced size 1 wind slab and loose dry avalanches. Explosive control work on steep shady treeline features produced no results.

Over the weekend near Fernie, storm slabs were reactive to explosives size 2-3 on northeast aspects in the alpine and upper treeline. We received several reports of rider triggered size 1 storm slabs in the alpine and loose dry avalanches up to size 1.5 around treeline.

On Friday, storm slabs up to size 2.5 ran naturally in addition to rider and explosive triggers.

Between Thursday and Sunday, numerous solar triggered loose wet avalanches were reported up to size 1.5 in steep terrain on east to south aspects in the alpine and all aspects below treeline.

 

Snowpack Summary

5-10 cm of lightly wind affected recent snow sits over a sun/temperature crust on solar aspects and below 1800 m.

A rain crust buried somewhere in the 50-100 cm of last week's storm snow has been found as high as 2100 m and is well bonded to surrounding snow. At up to 10 cm thick, it effectively bridges any deeper instabilities in the snowpack.

In areas and elevations where the rain crust is thinner, we continue to monitor a potentially weak interface 50-100 cm deep. It consists of sun and freezing rain crusts as well as weak faceted crystals on shaded aspects.

Although we haven't seen recent activity on a couple of weak layers buried in January, they still appear in snowpack models and local operators continue to track them. These consist of a layer of surface hoar and a crust buried more than 1m deep in most places.

The lower snowpack is generally well consolidated, with a crust/facet layer from early December found near the ground. It is currently considered dormant but could become active later this season.

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Wind Slabs

An icon showing Wind Slabs

The most likely places to trigger a wind slab include unsupported convex roll-overs and where recent snow sits over a crust.

Aspects: East, South East, South, South West, West, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 9th, 2022 4:00PM

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