Avalanche Forecast

Issued: Dec 14th, 2023 4:00PM

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

SH, Avalanche Canada

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N, Field, Little Yoho.

Strong winds and 5-10cm of snow will keep the hazard elevated for the next few days.

Summary

Confidence

Moderate

Avalanche Summary

Lake Louise ski patrol remote triggered a size 1.5. The feature was at treeline and was a reloaded bed surface from a previous avalanche. No other avalanches were observed, but visibility was poor for most of the day.

Snowpack Summary

Wind slabs are prevalent from previous strong winds. Last week's storm snow at treeline settled to 20-40cm. A rain crust up to 7cm thick exists within the storm snow as high as 2300. It has been observed to be more prevalent in the southern part of the region. This all overlies the deep persistent weak layers, consisting of surface hoar and basal facets. Treeline depths range from 50-80cm.

Click here for the snow profile done on Tuesday in the Dolomite peak area.

Weather Summary

Up to 10cm should fall by Friday morning. Snow will stop on Friday morning, winds will increase to 60kmh from the southwest, and temperatures will start in the -10 to -12C range, warming over the day. Friday night into Saturday will see extreme winds and no snow.

For more information, click Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

SW winds will ramp up to strong Friday afternoon, creating new wind slabs in alpine and exposed treeline terrain. Any new slab development will add to the previous ones formed last week. If initiated, these slabs may step down to the deeper weak layers.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

Weak layers exist near the snowpack's base, consisting of surface hoar and facets. If initiated, these can cause larger avalanches and potentially run further than expected to below treeline in gully features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Valid until: Dec 15th, 2023 4:00PM