Avalanche Forecast

Issued: Mar 28th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Recent new snow with strong wind has formed storm slabs that are likely still reactive at upper elevations, especially in wind loaded areas.

Keep in mind that the sun can quickly initiate natural avalanche activity and weaken cornices, especially at this time of the year.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

SUNDAY NIGHT - Cloudy with clear periods / moderate northwest wind / alpine low temperature near -4 

MONDAY - Sunny / moderate to strong north wind / alpine high temperature near -2 / freezing level 1000 m

TUESDAY - Mainly cloudy / moderate northwest wind / alpine high temperature near -4 / freezing level 1000 m

WEDNESDAY - A mix of sun and cloud / moderate west wind / alpine high temperature near 5 / freezing level 2300 m

Avalanche Summary

Avalanche activity is expected to decrease on Monday, however reactive storm slabs are still anticipated, particularly in wind loaded areas at higher elevations. Cornices are large and should be given a wide berth, especially when the sun comes out.

A natural avalanche cycle likely occurred during the day on Sunday. 

Snowpack Summary

A mix of rain and snow brought 30-50 cm/mm of precipitation to the region since Saturday night, accompanied by moderate to strong southerly winds. This precipitation fell on about 30-50 cm of older snow that fell last week. 

Rain at lower elevations has likely soaked the snowpack, which is expected to freeze into a crust with falling temperatures. 

Along ridgelines, cornices are large and may weaken when the sun comes out on Monday.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be aware of highly variable recent wind loading patterns.
  • Brief periods of sun could quickly initiate natural avalanche activity.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Storm Slabs

An icon showing Storm Slabs

30-40 cm of fresh snow has formed widespread storm slabs at upper elevations. These are expected to remain reactive to human triggering on Monday, especially in wind loaded areas. A change in wind direction on Monday means that wind loading may be found on many aspects.

With so much new snow, even brief periods of sun can trigger natural avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large and looming along many ridgelines, and have likely grown with the recent snow and wind. They become increasingly weak when the sun comes out.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 29th, 2021 4:00PM