Avalanche Forecast

Issued: Mar 30th, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Conditions may change quickly with rain or strong solar input. Be ready to scale back your exposure to avalanche terrain if the surface crust breaks down.

Cautious route-finding will be important at upper elevations as wind slabs may be reactive to human triggering.

Summary

Confidence

Low - Uncertainty is due to how quickly the snowpack will recover and gain strength. Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

WEDNESDAY NIGHT: Partially cloudy with flurries. Freezing level dropping to 500 m. 20-40 km/h northwesterly winds. 

THURSDAY: Mainly cloudy with scattered flurries. Freezing level rising to 1200 m. 15-35 km/h westerly winds.

FRIDAY: Partially cloudy with isolated flurries. Freezing level rising to 1500 m. 10-25 km/h southwest winds.

SATURDAY: Cloudy with flurries. Freezing level rising to 1600 m. 20-30 km/h southwest winds. 

Avalanche Summary

On Tuesday, a widespread natural avalanche cycle occurred with storm/wind slabs up to size 3 on all aspects, with the most reactivity noted on south-facing aspects. Numerous wet loose and wet slab avalanches occurred at treeline and below (size 1-2).

A few notable deep persistent slab avalanches occurred on Monday and Tuesday. These slabs are suspected to have failed on the early December crust near the base of the snowpack.

A widespread wet loose/slab natural avalanche cycle up to size 3 occurred on Monday on all aspects and elevations.

On Monday, a size 1.5 skier-triggered wind slab occurred on south aspect in the alpine. This wind slab failed on a slick crust below the new snow. 

The last persistent slab avalanche in the region was on March 25th. This layer is expected to become dormant after being tested by significant warming followed by cooling temperatures. 

Snowpack Summary

5-15 cm of new snow overlies up to 20 cm of denser snow above 2000 m. Southwest winds may form small wind slabs in lee terrain features. Below 2000 m on all aspects and to mountain top on solar aspects, a crust or moist snow can be found. Below the crust, the top 10-50 cm of the snowpack is moist. 

Several other crust layers exist in the upper snowpack, that have shown no recent reactivity. The remainder of the snowpack is well-bonded.

Terrain and Travel

  • Cornices become weak with daytime heating or solar exposure.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Wet Slabs

An icon showing Wet Slabs

Avoid avalanche terrain if the snowpack becomes wet and unsupportive to your weight. At lower elevations, a poor overnight crust recovery followed by above freezing temperatures and rain may cause wet slab and wet loose avalanches to continue on all aspects. 

 If the sun comes out on Thursday, wet loose activity can be expected on steep solar aspects at all elevations. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs

Wind slabs may exist in lee terrain features in the alpine and treeline, formed by recent snowfall and westerly winds. These wind slabs will be most reactive where they overlie a slick crust.  

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Springtime cornices are large and unpredictable. Give them a wide berth when travelling at ridge crest and avoid overhead exposure, especially when the air temperature is warm or solar radiation is strong.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Mar 31st, 2022 4:00PM

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