Avalanche Forecast

Issued: Apr 15th, 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 and Cornices.

Avalanche Canada wlewis, Avalanche Canada

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Monitor surface conditions as you move through aspects and gain elevation. Watch for dense, wind affected snow at higher elevations and moist or wet surface snow if the sun starts to shine. 

Check out the new forecaster blog if you're considering big lines this weekend.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack. Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

A cool and unsettled flow will affect coastal regions into the weekend. Convective flurries are expected in isolated areas and may be heavy at times. 

FRIDAY NIGHT: Some cloud overnight with light easterly winds. Freezing levels drop to 500 m.

SATURDAY: A mix of sun and cloud with light easterly winds. Freezing levels rise to 1400 m. Isolated flurries are expected to bring trace amounts during the day, and around 5 cm overnight.

SUNDAY: Clouds clear in the afternoon with increasing southeasterly winds. Freezing levels rise to 1500 m. No snowfall is expected. 

MONDAY: Snow begins in the morning with 10-15 cm expected, freezing levels reach 1300 m. Strong southerly winds ease to moderate over the day with mostly cloudy skies. 

Avalanche Summary

On Thursday, strong periods of sun triggered a cornice fall that produced a size 3 slab avalanche on a northeast slope around 1800 m. This avalanche failed on a deep weak layer within the snowpack, which is considered unlikely to occur from human or natural triggers at this time - except for large cornice falls. 

Sunshine also triggered loose avalanches to size 1.5 out of steep south facing features. Naturally triggered slab avalanches were reported on a north and east aspects around 1700 m. A rider triggered a size 1 slab avalanche on a south west aspect at 2100 m.

Snowpack Summary

10 to 30 cm of wind-affected snow sits above a crust or hard surfaces at higher elevations. Small wind slabs may be found at high elevations on south and west facing slopes from recent easterly winds. A melt freeze crust likely sits on the surface at lower elevations and on sun affected slopes. Periods of sun may soften or break down the crust throughout the day.

Various melt-freeze crusts exist in the upper to middle snowpack, which reports suggest are bonding well. The lower snowpack is considered strong and well settled at this time. 

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Carefully evaluate steep lines for wind slabs.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Wind Slabs

An icon showing Wind Slabs

Pockets of wind slabs may be found in steep terrain features near ridges from recent northeast winds. Watch for wind affected snow near ridgelines and around mid slope rollovers.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices may be weak and reactive to human triggers. They are a significant hazard alone, and may produce large slab avalanches as they fall onto the slope below. Cornice falls are more likely as temperatures warm each day, or when strong sunshine is present. 

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 16th, 2022 4:00PM