Avalanche Forecast

Issued: Mar 15th, 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 jfloyer, Avalanche Canada

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Conditions are mostly favourable for travel in avalanche terrain. Pay attention to steep, south-facing slopes as they heat up during the day and be mindful of large cornices.

Summary

Confidence

High -

Weather Forecast

MONDAY NIGHT: Clear and cold.

TUESDAY: Sunny with a few clouds, no snow expected. Freezing level rising to about 1500 m. Light southerly wind.

WEDNESDAY: Sunny with a few clouds, no snow expected. Freezing level rising to about 1700 m. Moderate southerly wind.

THURSDAY: Sunny, becoming cloudy through the day. Freezing level rising to about 2000 m. Moderate to strong southerly wind.

Avalanche Summary

On Sunday, only small loose wet avalanches were observed.

On Saturday in the north Monashees, which is outside of but very close to the eastern side of the region, there was a very large, size 3.5 avalanche reported. It was triggered by a cornice and stepped down to a deeper persistent layer.

Snowpack Summary

5-15 cm of recent new snow and moderate southwesterly winds have formed fresh wind slabs below alpine ridgetops. Dry snow can be found on north aspects and crusty snow surfaces exist on solar aspects. Large cornices loom over alpine ridges.

A persistent weak layer made up of surface hoar at treeline elevations and a crust with facets in the alpine on solar aspects can be found down 50-150 cm in some parts of the region. Only one recent avalanche has been reported on a deeper layer and this involved a very heavy trigger (a cornice).

Terrain and Travel

  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent convective flurries in parts of the region, solar radiation, and light to moderate winds may have formed wind slabs in isolated alpine locations. Steep, convex slopes below alpine ridgetops are the most likely places to trigger these slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Where cornices exist they pose a threat both from the potential for them to collapse under your feet (or machine) and from the potential to send large chunks of snow far down a slope. If anything can trigger the more stubborn persistent weak layers it's a large falling cornice. They are most likely to fail during the heat of the day.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 16th, 2021 4:00PM