Avalanche Forecast

Issued: Jan 8th, 2023 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Concerns for wind slabs in steep terrain and buried weak layers warrant careful terrain choices.

Summary

Confidence

Moderate

Avalanche Summary

Riders triggered small wind and storm slab avalanches at treeline elevations on Saturday. Small wet loose avalanches were observed below treeline.

It has been a week since the last reported avalanche on the weak layers described in the Snowpack Summary. These layers are increasing in strength, but could still be triggered in specific areas.

Snowpack Summary

Recent strong southerly wind formed wind slabs in lee terrain features near ridges. The recent 20 to 30 cm of storm snow continues to settle in sheltered terrain. Moist snow or a hard crust is found below around 800 m.

Several persistent weak layers may be found in the top meter of the snowpack. These include a surface hoar layer buried on Dec 28 found 40 to 60 cm deep and a facet layer buried on Dec 23 found 60 to 100 cm deep. In alpine terrain, triggering one of these layers is most likely on steep rocky slopes where they present as facets. In treeline terrain, the layers are most likely triggered on steep slopes in open trees where they present as preserved surface hoar.

Weather Summary

Sunday Night

Cloudy with trace precipitation, 20 to 30 km/h southeast wind, treeline temperature -3 °C, freezing level 600 m.

Monday

A mix of sun and cloud with no precipitation, 20 km/h east wind, treeline temperature -3 °C, freezing level 700 m.

Tuesday

Cloudy with snowfall, accumulation 5 to 10 cm, 20 km/h southeast wind, treeline temperature -4 °C,

Wednesday

A mix of sun and cloud with no precipitation, 20 km/h southeast wind, treeline temperature -1 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be especially cautious as you transition into wind affected terrain.
  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
  • Use conservative route selection and resist venturing out into complex terrain.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent strong southerly wind formed wind slabs on north-facing terrain. Assess for slabs prior to committing to steep terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Triggering persistent slab avalanches remains possible due to several weak layers in the top metre of the snowpack. Facet layers are the primary concern in alpine terrain, while preserved surface hoar layers are the concern in treeline terrain. Recent observations suggest these layers are gradually strengthening, but are still on the radar of professionals.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Jan 9th, 2023 4:00PM

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