Avalanche Forecast

Issued: Mar 10th, 2023 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Assess for wind slab as you gain elevation. Previous southeasterly winds have formed wind slabs on lee features in the alpine which may be reactive to human triggers.

Minimize time travelling on slopes below cornices. In shallow snowpack areas a cornice fall could trigger a deep persistent slab avalanche.

Summary

Confidence

Moderate

Avalanche Summary

A cornice triggered size 1.5 wind slab avalanche was reported on a northwest aspect in the alpine in the Duffey zone on Tuesday. No significant avalanches were reported in the past couple days.

Snowpack Summary

A new sun crust exists on or near the surface on solar aspects. Wind slabs could still be found near ridge crests in the alpine. These slabs sit on a variety of surfaces including sun crusts, facets, and previous wind effect. These recent winds have also formed large cornices. Around 20 cm of soft snow can be found in sheltered terrain.

The mid-snowpack is well consolidated.

This is not the case for the lower snowpack. There is a widespread weak layer of large sugary facets at the bottom of the snowpack. Recent avalanche activity on this layer has been confined to northern parts of the region in the Chilcotins. This layer remains a concern in shallow snowpack areas.

Weather Summary

Friday Night

Mostly cloudy with a few centimeters of new snow possible. Light southwest winds and a low of -8°C at 1800 m.

Saturday

Mostly cloudy with light flurries bringing a few centimeters of new snow. Light southerly winds and a high of -5°C at 1800 m.

Sunday

Cloudy with around 5 cm of new snow expected. Light to moderate southerly winds and a high of -4°C at 1800 m with freezing levels rising to 1200 m.

Monday

Stormy with up to 20 cm of new snow expected. Moderate to strong southeast winds and a high of -4°C at 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
  • Minimize your exposure time below cornices.

Problems

Wind Slabs

An icon showing Wind Slabs

Lingering wind slabs may remain reactive northerly aspects near ridge crests in the alpine.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A layer of weak facets sits near the base of the snowpack. This layer is most likely to be problematic in steep, wind-loaded terrain where the snowpack depth varies from thick to thin. Especially in the northern part of the region around the Chilcotins, Birkenhead, and Hurley.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 11th, 2023 4:00PM