Avalanche Forecast

Issued: Dec 2nd, 2020 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is below threshold. Known problems include Storm Slabs.

Avalanche Canada kdevine, Avalanche Canada

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The White Pass area has just seen what you might call a once in a lifetime storm. With over 100 cm of new snow and strong southwest wind, storm slabs are probably widespread and easy to trigger. Make conservative terrain choices while the new snow settles and stabilizes.

Summary

Confidence

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

Weather Forecast

WEDNESDAY NIGHT - Snow, 10-20 cm / south wind, 60-80 km/h / alpine low temperature near -2 / freezing level dropping to 1000 m

THURSDAY - A mix of sun and cloud with scattered flurries / south wind, 60-80 km/h / alpine high temperature near -3 / freezing level 900 m 

FRIDAY - Flurries, 5-10 cm / south wind, 25-50 km/h / alpine high temperature near -3

SATURDAY - Snow, 10-20 cm / south wind, 50-70 km/h / alpine high temperature near -2 

Avalanche Summary

A widespread natural avalanche cycle likely reached its peak during the height of the storm, however continued avalanche activity is expected. 

Though Thursday is expected to be cooler and drier than the last few days, storm slabs will likely be reactive to human triggers, and continued strong winds and wind loading may trigger natural avalanches as well. 

Snowpack Summary

The White Pass area has just been through what is probably one of the most epic storms in living memory. Over 100 cm of snow has fallen since Monday night. The Fraser weather station was up to 2 meters on Wednesday morning. With another 10-20 cm expected on Wednesday night, it's safe to say that it's piling up out there.

All of this new snow has arrived with strong southwest winds and warm temperatures, which means that widespread wind and storm slabs should be expected.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Carefully monitor the bond between the new snow and old surface.

Problems

Storm Slabs

An icon showing Storm Slabs

Over 100 cm of new snow has fallen in the White Pass area since Monday night. Though Thursday offers a short break from the storm, be aware that storm slabs may still be very reactive, especially in wind loaded areas. More snow is on the way for Friday and Saturday with strong winds, which will keep the hazard elevated and storm slabs likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Dec 4th, 2020 4:00PM