Avalanche Forecast

Issued: Apr 1st, 2021 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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High elevation north aspects are still offering good skiing and riding conditions, but this is likely where you'll find some overlap with wind slab distribution. Analyze slopes for wind loading patterns and seek out more sheltered, low density snow.

Summary

Confidence

High -

Weather Forecast

Thursday night: Cloudy with continuing scattered flurries bringing less than 5 cm of new snow. Moderate southwest winds.

Friday: Mainly cloudy with continuing isolated flurries, continuing overnight. Light to moderate southwest winds. Alpine high temperatures around -5 with freezing levels to 1600 metres.

Saturday: Cloudy with continuing isolated flurries, increasing overnight. Light to moderate south winds. Alpine high temperatures around -3 with freezing levels to 1700 metres.

Sunday: Clearing over the day with 10-15 cm of new snow from the overnight period. Light west winds. Alpine high temperatures around -5

Avalanche Summary

Reports from Wednesday included several size 1 (small) skier triggered slabs on south aspects observed running stubbornly on a recent crust layer. One recent natural size 2 cornice failure was also noted, as well as fairly widespread natural wet loose activity (to size 1) on steep solar aspects.

A natural avalanche cycle was occurred during the weekend storm, with widespread size 3-3.5 avalanches in the Selkirks and more limited activity in the Monashees to size 2, a few of them cornice-triggered. Storm slabs remained reactive to ski cuts on Monday, mostly around size 1 with a couple of skier remotes size 1-2 in the east of the region.

By Tuesday, storm slabs were showing signs of becoming more stubborn, showing limited propagation with a few explosive control results around size 2. A skier triggered size 2.5 involvement in neighboring Glacier National Park resulted in lost gear and minor injuries.

Snowpack Summary

Light accumulations of new snow have added to wind affected surfaces in alpine areas and to settled dry snow on more sheltered, shaded aspects above about 2000 metres. Below this elevation and on solar aspects it buries crusty surfaces. Below about 1500 metres, surface conditions of the diminishing snowpack will vary according to alternating light rain, wet flurries, and overnight refreezes.

At alpine and treeline elevations, a widespread crust exists (except on north-facing slopes above 1800 m) buried 50-100 cm deep. Overall the snow seems to be bonding well at this interface, although there have been a few isolated avalanches running on deeper crust layers over the past few weeks.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Extra caution is needed around cornices under the current conditions.
  • Be alert to conditions that change with elevation.

Problems

Wind Slabs

An icon showing Wind Slabs

More recent wind slabs could be reactive in wind loaded terrain features at upper elevations on Friday.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Cornices

An icon showing Cornices

Cornices are fragile due to rapid growth from recent snow and wind. Cornice falls are dangerous in their own right and they can also trigger slabs on slopes below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 2nd, 2021 4:00PM

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