Avalanche Forecast

Issued: Apr 1st, 2023 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Spring is a dynamic time of year where conditions can vary widely and change rapidly. Localized periods of heavy snowfall may form fresh, reactive storm slabs, while even short periods of strong sun can rapidly destabilize the upper snowpack.

Carefully assess your local conditions and pay attention to how the weather is affecting the snowpack throughout the day.

Summary

Confidence

Moderate

Avalanche Summary

Prior to Friday's storm, multiple cornice failures and wind slab avalanches were reported. Several cornice failures triggered size 2-3 wind slabs in the alpine. Several skier-triggered wind slabs were reported from north and west aspects.

As the storm arrived on Friday, isolated pockets of storm slab were reactive to rider traffic in wind-loaded terrain in the alpine.

At the time of publishing on Saturday, a few skier-triggered dry loose and storm slab avalanches have been reported, mainly from alpine terrain with the most reactivity noted in wind-loaded areas.

Snowpack Summary

15 to 30 cm of new snow arrived on Friday evening accompanied by strong southeast shifting southwest winds. This new snow buries a variety of surfaces that include a heavily wind-affected alpine and treeline and a crust at lower elevations and solar aspects.

The middle of the snowpack is strong and bonded. At the bottom of the snowpack, a layer of weak facets remains present and continues to be monitored for signs of reactivity.

Weather Summary

Saturday night

Clear periods with isolated flurries. Alpine temperatures drop to a low of -10 °C. Ridge wind southwest 10-30 km/h. Freezing level at valley bottom.

Sunday

A mix of sun and cloud with convective flurries, localized accumulation up to 10 cm. Alpine temperatures reach a high of -7 °C. Ridge wind light from the northeast. Freezing level rises to 1100 metres.

Monday

A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -5 °C. Ridge wind northwest 10-30 km/h. Freezing level rises to 1300 metres.

Tuesday

A mix of sun and cloud. Alpine temperatures reach a high of -5 °C. Ridge wind light from the northeast. Freezing level rises to 1300 metres.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Remember that in the spring strong solar radiation and warm temperatures can weaken the snow in a matter of minutes.
  • Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
  • Avoid freshly wind loaded terrain features.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

15 to 30 cm of storm snow arrived on Friday evening with strong southeast shifting southwest winds forming deeper, more cohesive slabs in lee terrain features.

Watch for fresh storm slab development during periods of heavy snowfall and avoid steep solar slopes during periods of strong sun.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Dry

An icon showing Loose Dry

In areas where the recent storm snow has not formed a cohesive slab, dry loose avalanches may initiate easily in steep terrain, particularly where they overlie a slick crust.

Avoid exposure to steep slopes during periods of strong sun. Even brief windows of strong sunshine could rapidly initiate natural dry loose avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 2nd, 2023 4:00PM