Avalanche Forecast

Issued: Dec 11th, 2022 4:00PM

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

Avalanche Canada trettie, Avalanche Canada

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Use extra caution at treeline where triggering a persistent slab is more likely. This layer will be easier to trigger on exposed slopes where wind slabs could have formed over surface hoar.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches have been reported in the past few days in the region.

Please continue to share any observations of photos on the Mountain Information Network!

Snowpack Summary

Variable winds throughout this region has redistributed the 20-40 cm of snow received last week into pockets of wind slab at higher elevations. In sheltered areas without wind effect loose dry snow can still be found.

The snowpack below this is generally weak. A layer of surface hoar, facets, and/or melt-freeze crust can be found down 40 to 60cm. This layer is most concerning at 1900m and below.

Snowpack depths range from 60cm at treeline to 140 cm in the alpine. Below treeline the snowpack is thin and faceted (weak) making it a challenge to access terrain in many areas without damaging your sled.

Weather Summary

Sunday Night

Flurries possible with trace amounts of new snow. Light westerly winds. Temperatures at 1800m around -10 .

Monday

A mix of sun and cloud with light flurries possible bringing trace amounts of new snow. Light northwest winds increasing throughout the day. Temperatures around -11 at 1800m.

Tuesday

A mix of sun and cloud with moderate northerly winds . Temperatures at 1800m around -9. No snowfall expected.

Wednesday

Mostly sunny with no new snow expected. Moderate northwest wind and temperatures around -10 at 1800m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Problems

Wind Slabs

An icon showing Wind Slabs

As the wind changes direction it is possible that wind slab could be found on all aspects in exposed terrain at treeline and above.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs

A layer of concern formed in mid-November is composed of faceted grains, surface hoar, and/or a hard crust and can be found down 40 to 60 cm. Each incremental snowfall and wind event is adding an additional load bringing the weak layer closer to its tipping point. As a cohesive slab builds above the weak layer it could quickly become reactive to natural or human triggers.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Valid until: Dec 12th, 2022 4:00PM