Avalanche Forecast

Issued: Apr 15th, 2022 4:00PM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low. Known problems include 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 fact that cornice falls are particularly difficult to forecast. 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: Flurries continue into the evening with 3 cm expected at the most. Freezing levels drop to valley bottom overnight, and winds remain light from the east.

SATURDAY: A mix of sun and cloud with light easterly winds. Freezing levels rise to 1400 m. Flurries bring trace amounts of snow during the day and around 3 cm overnight.

SUNDAY: Clearing skies with increasing southeasterly winds. Freezing levels rise to 1600 m. Isolated flurries are expected to bring trace amounts. 

MONDAY: Snow begins in the morning, with 5 cm expected over the day. Winds increase to strong from the south. Freezing levels reach 1500 m. 

Avalanche Summary

On Thursday a natural cornice fall was observed, that did not trigger an avalanche on the slope below. Further details are unknown. On Tuesday, size 1 and 2 natural and skier triggered wind slab avalanches were reported. These occurred at higher elevations on west facing slopes from the recent easterly winds.  

Looking forward, avalanche activity is unlikely given the current cool conditions with little snowfall expected each day. Always consider the possibility of pockets of wind slabs in steep exposed terrain, cornice failures around ridgelines, and wet loose avalanches if the sun is out.

Snowpack Summary

10 to 30 cm of dry, wind-affected snow sits above a crust or hard surfaces at higher elevations. Small wind slabs may be found at high elevations 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

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Make observations and assess conditions continually as you travel.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

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

Unlikely - Possible

Expected Size

1 - 3

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