Avalanche Forecast

Issued: Jan 2nd, 2023 4:00PM

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

Avalanche Canada rgoddard, Avalanche Canada

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An atypical coastal snowpack has created a tricky-moderate danger rating.

Avoid wind-loaded areas at upper elevations. If triggered, buried weak layers in the mid to lower snowpack can produce large destructive avalanches.

Be really mindful of the terrain you choose until the snowpack "normalizes."

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches reported in the last 24 hours. However, there have been many reports of people coming across debris from slightly older avalanches.

Please continue to post your observations and photos to the Mountain Information Network.

Snowpack Summary

Strong southwest winds have likely created hard wind-affected surfaces in open areas, and wind slabs in lee terrain features. The top layer of snow that fell near the end of last week overlies a rain crust that formed earlier in the week. This crust is thin at higher elevations and up to 5 cm thick below treeline.

In the mid-snowpack, a weak layer of surface hoar has been observed down 80 to 100 cm, this layer is most prevalent in shaded and sheltered areas.

The lower snowpack consists of weak, sugary crystals of facets and depth hoar.

Snowpack depths remain highly variable, roughly 50 to 200 cm at treeline.

Weather Summary

Monday Night

Mostly clear, no accumulation, winds south 15 to 30 km/h, temperatures -5 to -3 °C at 1500 m.

Tuesday

A mix of sun and cloud, trace accumulation, winds southwest 10 to 25 km/h, temperatures -10 to -5 °C at 2000 m.

Wednesday

A mix of sun and cloud, winds southeast 15 km/h, temperatures -7 °C at 2000 m.

Thursday

Mostly cloudy, up to 5 cm accumulation, winds southeast 15 to 25 km/h, temperatures -5 °C at 2000m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Be mindful that deep instabilities are still present and have produced recent large avalanches.
  • Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.

Problems

Wind Slabs

An icon showing Wind Slabs

Since Friday's storm, strong southerly winds redistributed 15 to 20 cm of new snow into deep deposits of wind slabs at higher elevations. These wind slabs may be reactive to human triggering, particularly where they overlie a rain crust created on December 26th.

Keep in mind that wind slab avalanches have the potential to step down to deeper weak layers creating large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

With the combination of a relatively thin snowpack and cold and dry temperatures earlier in the season, the lower snowpack consists of weak, unconsolidated facets and depth hoar crystals. Weak basal layers, a cautious approach to large open terrain features is required especially around rocky or thin areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

A weak layer, consisting of surface hoar, has been reported down 80 to 100 cm. This layer is of greatest concern on shaded, northerly aspects and in thinner snowpack areas where human-triggering is most likely.

Remote triggering is a concern for this layer. If triggered, this layer has the potential to step down to the weak faceted lower snowpack, creating large and destructive avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Jan 3rd, 2023 4:00PM

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