Avalanche Forecast

Issued: Nov 29th, 2019 4:00PM

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

Avalanche Canada astclair, Avalanche Canada

Email

Soak up the sunshine, take stock of early season snowpack variability, and monitor for lingering pockets of wind slab in the alpine. 

Share what you see in the mountains this weekend via the MIN!

Summary

Confidence

Moderate - Confidence is due to a stable weather pattern with little change expected. Uncertainty is due to the limited number of field observations.

Weather Forecast

Friday night: Few clouds, alpine temperature -12 C, light east wind, no precipitation.

Saturday: Mostly sunny, alpine temperature -8 C, light variable wind, no precipitation.

Sunday: Increasing cloud cover, alpine temperature -6 C, light southerly wind, no precipitation.

Monday: Mostly cloudy, alpine temperature -8 C, southwest wind increasing to moderate, isolated flurries with 2-5 cm of accumulation possible.

Avalanche Summary

Avalanches are decreasing in likelihood, but it still may be possible to trigger wind slabs in isolated pockets in the alpine. This is a great MIN report from Wednesday that helps to paint the picture of these wind slab avalanches.

If you see anything while out in the field this weekend, please consider sharing that information with us and the backcountry community via the Mountain Information Network.

Snowpack Summary

With this week's clear and cold weather, last weekend's storm snow is losing strength, except where it has been drifted into wind slabs in the alpine. Variable winds previously redistributed the 20-30 cm of recent snow into wind slabs that may still be possible to trigger in isolated areas. These slabs could be more reactive where they overly a weak layer of surface hoar (feathery crystals). With few recent field observations, there is uncertainty as to the current distribution and reactivity of these layers. Generally, the prolonged inactive weather pattern has improved snowpack stability in the short term.

Snow line sits around 1200 m, and snow depths range from 80-130 cm at treeline elevations. A variety of crusts from late October are buried deeper in the snowpack (down 50 to 100 cm). 

Problems

Wind Slabs

An icon showing Wind Slabs

Strong and variable winds have redistributed the 20-30 cm of snow from last weekend's storm into cohesive slabs that may still be possible to trigger in the alpine in isolated pockets. These slabs could be more reactive where they overly a weak layer of surface hoar that formed on a crust.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Nov 30th, 2019 5:00PM