Avalanche Forecast

Issued: Feb 24th, 2024 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Tricky conditions exist with buried weak layers. Expect wind slabs to form, adding load to a weak snowpack

Stick to conservative terrain and avoid large features at treeline and above

Summary

Confidence

Moderate

Avalanche Summary

Wind slabs continued to show reactivity to human triggers on Friday with up to size 1.5 reported.

Activity is expected to increase on Sunday as snow and wind develop fresh slabs over weak snow surfaces.

Snowpack Summary

By Sunday evening, up to 20 cm of new snow is expected. This new snow will fall over a crust on south facing slopes, or over settling snow that overlies previous weak surfaces of crusts, facets or wind affect.

Roughly 50-60 cm of snow now sits above a widespread crust from late January. Weak grains like facets or more isolated surface hoar may be found above this crust. This problematic layering remains a concern with recent avalanche activity and snowpack tests showing reactivity. As minimal snowfall is forecast this layer is not expected to produce natural avalanches, but human triggering remains very possible.

Weather Summary

Saturday Night

Cloudy with up to 5 cm of new snow expected. 30-40 km/h southwest winds. Freezing levels remain around 1500 m.

Sunday

Cloudy with 5-15 cm of new snow. 40-60 km/h southwest winds. Treeline temperature -3 °C with freezing levels steady around 1500 m.

Monday

Mostly cloudy with isolated flurries. 20-30 km/h southwest winds. Treeline temperatures drop to -12 °C with freezing levels at valley bottom.

Tuesday

Mostly cloudy with possible sunny breaks. No snow is expected. 20-30 km/h southwest winds. Treeline temperatures around -12 °C with freezing levels at valley bottom.

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.
  • Wind slabs are most reactive during their formation.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Snow and wind will build fresh slabs, most reactive where they overly a crust or facets.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Recent observations show the problematic early February layer of facets on crust becoming increasingly triggerable. Avalanches triggered on this layer will be large and destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Feb 25th, 2024 4:00PM

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