Avalanche Forecast

Issued: Jan 18th, 2022 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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New wind slabs may form by the end of the day.

Summary

Confidence

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

Weather Forecast

TUESDAY NIGHT: Increasing clouds with early-morning precipitation, accumulation 1 cm, 20 km/h southwest wind, alpine temperature -10 C.

WEDNESDAY: Cloudy with snowfall, accumulation 5 cm, 40 km/h southwest wind, alpine temperature -9 C.

THURSDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 50 km/h southwest wind, alpine temperature -5 C, freezing level 1100 m.

FRIDAY: Mostly cloudy with intermittent snowfall, accumulation 2 to 5 cm, 60 km/h west wind, alpine temperature -4 C, freezing level 1200 m.

Avalanche Summary

Widespread avalanche activity was observed on Sunday and Monday. The avalanches were generally wind slabs in exposed terrain at higher elevations, storm slabs, and loose wet at low elevations. In the centre of the region, some of the avalanches failed on the weak layers described in the snowpack summary.

Avalanche activity may increase during Wednesday's storm, particularly into the evening as snow further accumulates from the incoming storm.

Snowpack Summary

Around 5 cm of snow is expected by sunset on Wednesday, with more snow forecast overnight. The snow will fall with strong southwest wind, forming new thin slabs in lee terrain features at higher elevations. Below around 1200 m in the south of the region, the snow will fall onto a melt-freeze crust.

Two weak layers may exist. A layer of surface hoar may be found around 30 cm deep, particularly in the centre and north of the region. A widespread layer of faceted grains is found around 40 to 60 cm deep, which formed during the cold spell in late December and early January. These layers have been most reactive in the central portion of the region.

In thin snowpack areas, the base of the snowpack is composed of weak faceted grains around various melt-freeze crusts, which are considered dormant at this time.

Terrain and Travel

  • Wind slabs are most reactive during their formation.
  • Be careful as you transition into wind affected terrain.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs may form over the day as new snow and strong southwest wind impact the region. These slabs will sit on previously reactive wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 19th, 2022 4:00PM