Avalanche Forecast

Issued: Dec 23rd, 2018 4:21PM

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

Avalanche Canada kdevine, Avalanche Canada

Email
Wind slabs will likely be found at upper elevations and may be reactive to human triggering, especially in lee features. In any areas have received more than 30 cm of new snow in the past 24 hours, the hazard is likely "Considerable" in the alpine.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

SUNDAY NIGHT - Flurries, 5-10 cm / southwest to west winds, 30-60 km/h / alpine low temperature near -5°c. MONDAY - Flurries, 5-10 cm / west winds, 20-40 km/h / alpine high temperature near -5°c. TUESDAY - Flurries, 5-10 cm / light northwest winds / alpine high temperature near -5°c, low temperature near -7°c. WEDNESDAY - Flurries, 5-10 cm / southwest winds 20-30 km/h / alpine high temperature near -3°c, low temperature near -5°c.

Avalanche Summary

No new avalanches were reported in the region on Saturday. Several small natural and explosives triggered avalanches (size 1-1.5) were reported in the region on Friday.

Snowpack Summary

10-30 cm of new snow sits on a melt-freeze crust to approximately 1000 m. Above 1000 m this new snow is just adding to the 150+ cm of snow that has fallen over the past week. Strong winds have likely formed wind slabs at upper elevations, especially in lee features. Expect to find more reactive slabs in wind loaded areas, and especially in places that received high snowfall amounts over the weekend. 120-200 cm of snow sits on a weak layer that was a concern when the first waves of the storm hit the coast, but the strength of this layer has generally improved over the past week. This layer consists of surface hoar (feathery crystals), facets (sugary snow), and crusts that formed during the dry spell in early December. The surface hoar is most prevalent and has most recently been reactive between 1100-1300 m in more northern portions of the region, and is something to keep in mind if you plan to travel to areas like Ningunsaw. Deeper in the snowpack, there are several crusts, including an early season crust with facets near the bottom of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent fresh snow and wind will likely be forming wind slabs at upper elevations.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 24th, 2018 2:00PM