Avalanche Forecast

Issued: Mar 28th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Recent fresh snow with strong wind has formed widespread storm slabs that are likely still easy for humans to trigger, especially in wind loaded areas at upper elevations.

Summary

Confidence

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

Weather Forecast

SUNDAY NIGHT - Clear periods / moderate to strong northwest wind / alpine low temperature near -13 

MONDAY - A mix of sun and cloud / moderate to strong northwest wind / alpine high temperature near -9 

TUESDAY - Mainly cloudy with a few flurries / moderate to strong west wind / alpine high temperature near -6 / freezing level 1100 m

WEDNESDAY - Cloudy with scattered flurries / moderate to strong southwest wind / alpine high temperature near -6 / freezing level 1000 m

Avalanche Summary

Avalanche size and sensitivity are expected to decrease over the next few days, however, reactive storm slabs are still anticipated, especially in wind loaded areas at upper elevations. If the sun comes out on Monday, it could quickly trigger natural avalanches within the new snow. Cornices are large at this time of year, and they become weaker when the sun hits them.

There are no recent reports of avalanches, however, it's likely that a natural avalanche cycle occurred over the weekend, particularly in places that received higher snowfall amounts.

Snowpack Summary

15-25 cm of snow has fallen in the region since Friday night, accompanied by strong southwest wind. Much of this precipitation fell as rain below treeline. The surface has likely frozen into a crust at lower elevations.

Buried 70-120 cm deep, a spotty layer of surface hoar may exist on sheltered north aspects, as well as a crust on south aspects and below 1450 m. Recent observations suggest that this interface is bonding.

The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and have the potential to be triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Avoid freshly wind loaded terrain features.
  • Be aware of highly variable recent wind loading patterns.
  • Even brief periods of direct sun could produce natural avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Fresh and reactive storm slabs are likely to be encountered, especially in wind loaded areas at upper elevations. A change in wind direction on Monday means that wind loading may be found on many aspects.

Keep in mind that brief periods of sun can initiate natural avalanches, especially in areas that saw high snowfall amounts on the weekend.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

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

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