Avalanche Forecast

Issued: Apr 22nd, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

All blow and no snow! Strong wind and light snowfall may form fresh and reactive wind slabs at higher elevations.

Avoid freshly wind-loaded features, especially near ridge crests, roll-overs and in steep terrain.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

FRIDAY NIGHT: Cloudy with snowfall, 5 cm of accumulation. Wind increasing to moderate from the south. Freezing level dropping to valley bottom. Treeline temperature around -8 C.

SATURDAY: Continued snowfall may become mixed with rain as freezing levels rise to 1300 m. Snowfall accumulation of 2 to 5 cm. Moderate wind from the southeast.

SUNDAY: Flurries, around 5 cm of accumulation at higher elevations. Freezing levels rise to 1500 m in the afternoon and drop to about 1000 m overnight. Moderate southeasterly wind.

MONDAY: Continued precipitation, 5 cm of new snow at higher elevations. Freezing levels rise to 1500 m in the afternoon and drop to about 1000 m overnight. Light easterly wind.

Avalanche Summary

A large cornice failure was observed in the Cleveland riding area on Thursday. The full report can be seen here.

Looking forward to Saturday, fresh and reactive wind slabs are expected to form in lee areas in the alpine and treeline. Wet loose avalanches will be possible at low elevations with rain and warm temperatures. These avalanches will likely be limited to small releases on isolated slopes in extreme terrain.

Reports are limited at this time of year. Please let us know what you're seeing by filling out a MIN report!

Snowpack Summary

New snow and southerly winds are expected to create fresh deposits of wind slab in the alpine and exposed treeline. This 5-10 cm of new snow overlies a faceted and heavily wind-affected surface from last week's strong northerly winds. Large surface hoar has also been found in sheltered areas. On south and west-facing slopes up to 1400 m, a surface crust from spring sunshine can be found, while other aspects hold dry snow. The mid-snowpack is generally strong, overlying weak basal facets at the base of the snowpack. 

Check out this MIN report from the Yukon Field Team for a picture of conditions prior to the storm.

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Wind slabs are most reactive during their formation.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and southerly winds are expected to form fresh and reactive wind slabs in lee areas in the alpine and isolated, exposed areas at treeline. 

Use caution entering lee terrain features below ridges. The snow could slide easily where it rests on a hard melt-freeze crust, surface hoar, or facetted snow. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

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

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Apr 23rd, 2022 4:00PM