Avalanche Forecast

Issued: Jan 25th, 2021 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Yukon.

New wind slabs may form with sustained northeast wind. Cold temperatures should keep the remainder of the snowpack tight.

Summary

Confidence

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

Weather Forecast

MONDAY NIGHT: Cloudy with light snowfall, trace accumulation, 10 to 20 km/h north wind, alpine temperature -15 C.

TUESDAY: Partly cloudy, 40 km/h northeast wind, alpine temperature -20 C.

WEDNESDAY: Clear skies, 40 km/h northeast wind, alpine temperature -22 C.

THURSDAY: Partly cloudy, 20 km/h southwest wind, alpine temperature -19 C.

Avalanche Summary

No avalanches were reported over the weekend.

Looking forward, new wind slabs may form with sustained northeast wind. These slabs could be triggered by riders and perhaps naturally as the wind continue to load starting zones.

Snowpack Summary

In sheltered terrain, soft and consolidated snow may be found. In exposed terrain, a wind-affected snow surface prevails. Wind affected snow varies from wind-pressed snow to hard and thick wind slabs, which generally hardens with elevation.

A buried weak layer of surface hoar may still be found around 90 cm deep. It was found around Log Cabin and also in Powder Valley (see here). Avalanche activity on this layer hasn't been reported since the first week of January.

The lower snowpack is strong around White Pass, but a thinner and weaker snowpack structure is expected inland, such as in the Wheaton Valley and the south Klondike.

Terrain and Travel

  • Watch for areas of hard wind slab on alpine features.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Wind slabs are most reactive during their formation.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

A switch in wind to sustained northeast wind is forecast for Tuesday and Wednesday. This reverse-loading pattern could form slabs on atypical slopes. Air temperature is cold so the slabs may be sluggish, but use particular caution as they will be most reactive during their formation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 27th, 2021 4:00PM

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