Avalanche Forecast

Issued: Dec 28th, 2021 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 shorton, Avalanche Canada

Email

Cold dry weather continues. Wind slab avalanches will be possible to trigger on steep open slopes.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Cold arctic air will persist until Sunday.

TUESDAY NIGHT: Mostly clear skies, no precipitation, moderate wind from the north with gusts to 40 km/h, treeline temperatures drop to -15 C.

WEDNESDAY: Mostly sunny with some afternoon clouds, no precipitation, moderate wind from the northwest with gusts to 40 km/h, treeline temperatures around -10 C.

THURSDAY: Mostly cloudy, light flurries with 5-10 cm of low density snow, light wind from the northwest, treeline temperatures around -8 C.

FRIDAY: Sunny skies, light wind from the north, treeline temperatures around -10 C.

Avalanche Summary

Some small avalanches were reported on the North Shore mountains over the weekend. These include a few size 1 skier triggered slabs on convex rolls in the Seymour backcountry (see photos in the MIN reports here and here) and some loose dry avalanches in the top 10 cm of low density snow.

Similar avalanche activity can be expected in the upcoming days, although there will be potential for larger slabs at upper elevations if the wind increases and begins to transport snow.

Snowpack Summary

Cold weather has left 20-40 cm of low density snow on the surface. There is potential for northerly winds to begin transporting this snow into wind in unusual locations. This low density snow sits above a mostly settled and bonded snowpack with a few crusts in the top 100 cm. Higher terrain around Squamish may have a lingering weak layer of facets above a crust that formed in early December. This layer is now 150-200 cm deep and has likely transitioned from stubborn to unreactive.

Terrain and Travel

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Make observations and assess conditions continually as you travel.

Problems

Wind Slabs

An icon showing Wind Slabs

Winds have shifted from south to north with an ample supply of light, cold snow to drift into slabs. Watch for unusual cross-loading or reverse-loading patterns in wind-exposed areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 29th, 2021 4:00PM