Avalanche Forecast

Issued: Jan 17th, 2024 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Wind has modified the snow surface on all aspects, and down to valley bottom in most places. Soft snow is sparse.

Alpine wind slabs may still avalanche under the weight of a human or machine.

Summary

Confidence

Moderate

Avalanche Summary

On Monday, a few large natural avalanches were reported in the highway corridor on both the Canadian and American sides of White Pass. These likely occurred with wind loading recent storm snow into lee features.

Wind slabs may continue to be rider-triggerable on all aspects in the alpine on Thursday.

Snowpack Summary

Variable direction, moderate to strong winds have formed wind slabs on all aspects and at all elevations. In isolated areas sheltered from the wind, you may find up to 10 cm of soft snow on the surface.

The middle of the snowpack is settled and strong.

Right above the ground, you'll find 30-40 cm of loose, sugary, faceted snow under a crust.

Weather Summary

Wednesday Night

Mostly cloudy. Trace of new snow expected. Strong to extreme northeast ridgetop wind. Treeline temperature falling to around -18 °C.

Thursday

Partly cloudy. No new snow expected. Moderate to strong east or northeast ridgetop wind. Treeline temperature around -20 °C.

Friday

Mostly sunny. No new snow expected. Moderate to strong northeast ridgetop wind. Treeline temperature around -20 °C, with possible temperature inversion.

Saturday

Partly cloudy. Trace of snow expected. Moderate northeast ridgetop wind. Temperature inversion breaking down, treeline temperature around -18 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Even a small avalanche can be harmful if it pushes you into an obstacle or a terrain trap.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Approach lee and cross-loaded slopes with caution.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

Wind Slabs

An icon showing Wind Slabs

Variable winds have formed wind slabs on all aspects in exposed terrain. These slabs seem to be bonding at lower elevations, but may still be reactive in the alpine. Due to recent strong wind, slab formation may be partway down a slope.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 18th, 2024 4:00PM