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Avalanche Forecast

Dec 7th, 2020–Dec 9th, 2020
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold

Regions: Yukon.

  

Recently formed wind slabs will likely be reactive to human triggers and could step-down to deeper weak layers, resulting in large avalanches.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

  

MONDAY NIGHT: Cloudy with flurries; 3-5 cm. / Strong, southwest ridgetop wind / alpine low temperature -10 / Freezing level valley bottom.

TUESDAY: Mostly cloudy with isolated flurries; 0-3 cm. / Strong, southwest ridgetop wind / alpine high temperature -6 / Freezing level valley bottom.

WEDNESDAY: Mix of sun and cloud / Moderate, southwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.

THURSDAY: Mostly cloudy / Light, southwest ridgetop wind / alpine high temperature -11 / Freezing level valley bottom.

Avalanche Summary

A widespread natural avalanche cycle with numerous avalanches up to size 3 was reported in the White Pass area last week, mostly during the height of the storm (Monday-Wednesday) Check out this MIN report detailing these observations.

Recently formed wind slabs will likely be reactive to human triggers and could step-down to deeper weak layers, resulting in large avalanches.

Observations in this region are very limited, please post your observations to the Mountain Information Network.

Snowpack Summary

  

10-20 cm of new snow over the weekend and ongoing strong southwesterly winds continue to build fresh wind slabs sitting on top of the widespread storm slabs created last week.

The White Pass area received over 100 cm of new snow last week with strong southwest winds. Total snowpack depth is around 175 cm in sheltered areas around White Pass.

In drier areas such as the Wheaton Valley, total snowpack depths are likely in the 50-100 cm range and are probably quite variable due to wind transport. The base of the snowpack in this area may consist of some weak, sugary facets. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid lee and cross-loaded terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Watch for areas of hard wind slab on alpine features.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Avalanche Problems

Wind Slabs

  

Recently formed wind slabs will likely be reactive to human triggers and could step-down to deeper weak layers, resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1.5 - 2.5