Avalanche Forecast

Issued: Nov 23rd, 2015 9:43AM

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

Avalanche Canada swerner, Avalanche Canada

Given the very limited information on hand for this bulletin, I would tread cautiously and take the time to gather snowpack information as I go. As always, we would love for you to submit any observations from your day to the MIN.

Summary

Weather Forecast

The first arctic outbreak of the season remains stationary bringing outflow winds with a cooler air mass. This blocking high pressure pattern will likely keep things cold and dry, however, an above freezing layer may develop on Wednesday around the 1000 m level and could reach as far inland as Smithers.Tuesday: Ridgetop winds blowing Strong from the N-NE and temperatures at treeline elevations hovering around -12.0.Wednesday/ Thursday: Freezing levels will remain at valley bottom with average treeline temperatures near -5.0. Light winds will continue from the N-NE direction.

Avalanche Summary

No new avalanches have been reported. This may speak to a lack of observations rather than actual conditions. Newly formed wind slabs may remain sensitive to human triggering for the next few days, especially in areas with buried persistent weak layers.

Snowpack Summary

Reactive wind slabs are expected to have formed as a result of new snow, warm temperatures and strong westerly winds on Friday and Saturday. At lower elevations precipitation fell as rain, and more recent cooling has formed a refrozen crust. The reactivity of these new wind slabs will likely change with elevation and underlying snowpack structure. Due to limited observations, I have very little confidence in what that underlying structure may be, although faceting and surface hoar development may have occurred on shaded terrain. The region is now seeing moderate outflow winds from the N-NE which may be redistributing some of the new snow onto opposite slopes. This makes thing tricky and you may find new wind slabs on unsuspecting slopes and terrain features. If I were traveling in the mountains, I'd maintain an investigative approach and dig down to test for weak layers before committing to a slope. If you've been in the mountains, please share your observations on our Mountain Information Network.

Problems

Wind Slabs

An icon showing Wind Slabs
Watch for new wind slabs on opposite slopes due to changing winds from the north. New snow and strong winds on the weekend may have formed reactive wind slabs at higher elevations. Watch for wide propagations, especially in the lee of ridgecrests.
Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Be alert to conditions that change with elevation and use a cautious approach to terrain while gathering information along the way.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Nov 24th, 2015 2:00PM

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