Avalanche Forecast

Issued: Dec 26th, 2024 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 Persistent Slabs.

Avalanche Canada Avalanche Canada, Avalanche Canada

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Stay diligent with careful terrain selection and good travel habits. Fresh storm slabs in combination with tricky buried weak layers create a complex snowpack.

Summary

Confidence

Moderate

Avalanche Summary

On Tuesday, several skier-triggered persistent slabs (size 1) were reported in the Bonnigtons-MIN.

On Thursday, skiers near Rossland remote-triggered storm slabs (size 1-2) on north facing treeline and below treeline terrain. Natural storm slabs up to size 2 were also observed in the area.

Snowpack Summary

15 to 30 cm of new snow has fallen in the past 24 hours. Accompanying southwest winds have redistributed this new snow, forming deeper deposits on leeward slopes at higher elevations.

A crust is present near the surface at lower elevations, with moist snow likely near the valley bottom where precipitation falls as rain.

The upper snowpack continues to settle and bond well following significant snowfall over the last two weeks.

Weak layers of surface hoar or facets and a crust may persist in the mid-snowpack, and snowpack tests continue to indicate potential instability.

The lower snowpack is generally strong and well-bonded.

Weather Summary

Thursday Night

Cloudy with up to 10 cm of new snow. 15 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.

Friday

Mostly cloudy with up to 3 cm of new snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -6 °C.

Saturday

Cloudy with 5 to 20 cm of new snow. 15 to 40 km/h southwest ridgetop wind. Treeline temperature -3 °C.

Sunday

A mix of sun and cloud with up to 2 cm of new snow. 5 to 15 km/h northeast ridgetop wind. Treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Surface hoar distribution is highly variable. Avoid generalizing your observations.

Problems

Storm Slabs

An icon showing Storm Slabs

Recent snowfall and southwest winds have formed fresh storm slabs that will be deepest and most reactive in wind-loaded areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Buried weak layers of surface hoar and facets on a crust are now buried 40 to 100 cm deep. Increased load from new snow may make these layers more reactive. Be especially cautious on steep, open slopes at treeline and below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 27th, 2024 4:00PM

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