Avalanche Forecast

Issued: Dec 25th, 2022 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Wind Slabs and Persistent Slabs.

Avalanche Canada jpercival, Avalanche Canada

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Watch for wind effect in recent storm snow. Expect wind loading around ridgelines and in mid slope terrain features.

Strong winds have transported snow lower on slopes than you expect.

Deeper weak layers remain a concern for step down avalanches in wind loaded terrain.

Summary

Confidence

Moderate

Avalanche Summary

Activity from Friday was limited to small loose dry avalanches in steep terrain features.

On Tuesday and Wednesday explosive control in the region produced small avalanches with a depth of 10cm.

If you are headed into the backcountry please consider filling out a Mountain Information Network report.

Snowpack Summary

Sustained light to moderate southwest winds have continued to move snow, creating wind slabs on north and east facing terrain features. Wind slabs sit over hard wind affected surfaces, a layer of facets or surface hoar increasing reactivity.

The main concern is a layer of surface hoar, facets, or crusts buried 40 to 80 cm deep from mid November. Avalanche activity on this layer has tapered off but it could still be possible to trigger this layer in isolated terrain features near treeline. Triggering becomes more likely as temperatures rise.

Alpine snowpack distribution is variable, with depths ranging from 70 to 140 cm.

Weather Summary

Sunday Night

Cloudy with flurries bringing trace amounts of new snow. Moderate southwest winds and a high of -6°C .

Monday

A mix of sun and cloud with 5 to 15 cm of snow possible. Moderate southwest winds. Freezing levels rise to 1000 m. High temperatures of -5°C expected.

Tuesday

Mostly cloudy with snowfall 5 to 10 cm. Moderate to strong southwest winds. Freezing levels remain below 1000 m with alpine highs of -4°C.

Wednesday

Mostly cloudy with light snowfall. Moderate to strong southwest winds. Freezing levels remain below 1000 m with alpine highs of -4°C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong southwest winds will likely continue to form wind slabs in exposed terrain at treeline and above. These slabs will be found on east and north facing slopes sitting above facets and surface hoar, increasing reactivity and propagation.

Strong winds can move snow further down slope, look for wind loading in mid slope terrain features where wind may slow and deposit snow. Wind slab avalanches could step down to deeper layers.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A layer of surface hoar, facets and, a crust from mid November is buried around 40-80 cm deep. This layer has become hard to trigger but could still be sensitive to rider traffic on isolated slopes at treeline and below where the snow above feels stiff, slabby and consolidated.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Valid until: Dec 26th, 2022 4:00PM

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