Avalanche Forecast

Issued: Dec 21st, 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.

Avalanche Canada bchristie, Avalanche Canada

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Start on small slopes and check how well the new snow is sticking before committing to your line.

Avalanches are possible in wind loaded terrain.

Travel carefully due to early season hazards.

Summary

Confidence

Moderate

Avalanche Summary

Small, naturally triggered wet loose avalanches were observed in steep, rocky terrain on Wednesday.

If you do head into the backcountry please consider submitting observations and/or photos on the Mountain Information Network.

Snowpack Summary

Through the day on Friday 10-15 cm of new snow is forecasted to fall with moderate wind as the freezing level drops. This new snow should bond fairly well to the old surface. If the wind moves enough snow onto old, firm surfaces, at treeline and above, avalanches could become more likely.

The previous snow surface was moist at treeline and below, and a frozen crust in the alpine.

The mid and lower snowpack is made up of a series of crusts and rounded grains. The snowpack is generally well consolidated.

Overall, the snow depth remains shallow, especially on south facing slopes. Early season hazards are just below the surface.

Weather Summary

Thursday Night

Mostly cloudy, clearer near the US border. No new snow expected. Light to moderate southwest ridgetop wind. Treeline temperature around 0 °C. Freezing level around 1750 m.

Friday

Mostly cloudy. 10-15 cm of new snow expected, less in Manning Park. The storm will start with rain below 1500 m, but the freezing level will be at valley bottom by the end of the day. Moderate southwest ridgetop wind.

Saturday

Partly cloudy. Light snow expected overnight, stopping by the morning. Light southwest ridgetop wind. Treeline temperature around -7 °C.

Sunday

Mostly sunny. No new snow expected. Moderate south ridgetop wind. Treeline temperature around 0 °C, possible temperature inversion.

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.
  • Even a small avalanche can be harmful if it pushes you into an obstacle or a terrain trap.
  • Travelling on skis is hazardous due to a very shallow mountain snowpack.
  • Wind slabs may be poorly bonded to the underlying crust.

Problems

Wind Slabs

An icon showing Wind Slabs

This storm is coming in warm and going out cold. Where snow is falling, it should stick to the old surface fairly well. Avalanches are most likely where strong winds are forming deeper pockets of snow over old, smooth, hard surfaces.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 22nd, 2023 4:00PM