Avalanche Forecast

Issued: Jan 4th, 2024 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Continue to assess for signs of instability. Back off if you observe concerning evidence, such as avalanches, whumpfs, or shooting cracks.

Summary

Confidence

Moderate

Avalanche Summary

We didn't receive any reports of avalanche activity for Wednesday.

We've received notes on backcountry users experiencing whumpfs in the Babines, Grizzly Plateau, and around Hudson Bay Mountain. We suspect the whumpfing is from the failure of surface hoar layers that are described in the Snowpack Summary. Such observations suggest that humans could trigger avalanches where these layers remain intact.

Snowpack Summary

Up to 25 cm of soft snow exists in areas sheltered from the wind. The snow surface in wind-exposed terrain includes wind-stiffened snow or scoured surfaces including a hard melt-freeze crust or the ground. A small amount of new snow over a hard crust is found below treeline.

Two or more preserved surface hoar layers can be found buried between 35 cm and 80 cm deep in most parts of the region. These layers are most prominent at treeline and below treeline elevations above 1200 m, but they've also been observed in some alpine locations.

Snowpack depths at treeline vary across the region with generally deeper amounts (~150 cm) in the west and shallower (~80 cm) in the east.

Weather Summary

Thursday Night

Cloudy with 1 to 3 cm snow, south alpine wind 20 to 40 km/h, treeline temperature -7 °C.

Friday

Cloudy with 2 to 5 cm snow, south alpine wind 20 to 40 km/h, treeline temperature -6 °C.

Saturday

Mostly cloudy with trace snow, northwest alpine wind 10 to 20 km/h, treeline temperature -8 °C.

Sunday

Mix of sun and cloud with no precipitation, northwest alpine wind 10 km/h, treeline temperature -10 ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Carefully evaluate steep lines for wind slabs.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Several buried surface hoar layers may be found 35 to 80 cm deep. These layers only seem to be a problem at elevations above 1200 m.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

Southerly wind may form wind slabs in lee and cross-loaded terrain features near ridges. Assess for slabs prior to committing to large and consequential terrain features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Jan 5th, 2024 4:00PM