Avalanche Forecast

Issued: Dec 9th, 2020 3:00PM

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

Avalanche Canada mkoppang, Avalanche Canada

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Watch for windslabs as you transition into open wind affected terrain. Recent natural avalanche activity indicates that these windslabs can also be human triggerred. 

Summary

Confidence

High -

Weather Forecast

The storm is over unfortunately! Winds will be light to moderate out of the SW on Thursday as a high pressure system builds back in over the region. Temperatures are expected to cool dramatically with -17C forecast for thursday morning. 

Avalanche Summary

A few sz 2 windslabs were observed failing within the at the interface with the recent storm snow. These were up to 50m across, 40-60cm deep and ran to the top of their normal runouts. A noteable sz 2.5 was observed in the Black Prince area on a NE aspect that ran to the middle of its runout that looked to have entrained some wet snow. Black prince area also had numerous sz 2 avalanches down 15-20cm failing on surface hoar.  

Snowpack Summary

Up to 30cm of snow fell in the past 24hrs with only isolated variable winds in upper elevation. This new snow is overlying a variety of surfaces from surface hoar (up to 2100m) and crusts (solar aspects) that formed in the big warm up last week as well as hard windslabs. Carefully evaluate the bond of this new snow as it begins to strengthen over the next few days. The November crust is down 50-80cm now and continues to produce variable results. The snowpack felt a bit cakey along ridgelines on Wednesday so be watching for winds to increase making these windslabs more reactive. In some areas below 2000m the snowpack was moist...

Terrain and Travel

  • Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Don't let the desire for deep powder pull you into high consequence terrain.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

Problems

Wind Slabs

An icon showing Wind Slabs

New windslabs can be found along ridgelines in alpine and treeline areas. These are not widepsread at this time but they are overlying the previous windslabs from last week also. Watch for cakey or or that upside snow snowpack feel.   

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

The November crust continues to be a concern in the snowpack. Any avalanche in the upper snowpack will likely scrub down to these layers

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Dec 10th, 2020 3:00PM