Avalanche Forecast

Issued: Mar 11th, 2024 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Wind slabs are reactive to human triggers and buried weak layers remain capable of producing very large avalanches

Summary

Confidence

Moderate

Avalanche Summary

Small slabs were reactive to rider traffic on Sunday within the storm snow.

Over the weekend large persistent slab avalanches continued, triggered by riders and naturally by cornice falls onto the slope below. A fatal avalanche occurred in nearby Kananaskis Country on Sunday, where a similar snowpack structure exists.

Snowpack Summary

Around 20 cm of recent storm snow has fallen and been redistributed into deeper deposits on north and east facing slopes by winds. These slabs sit over a crust on sun affected slopes, surface hoar in sheltered terrain, and wind affected snow in exposed areas and currently do not appear to be bonding well.

A widespread crust with weak facets above remains a concerning layer for human triggering. Buried 80-150 cm deep, this layer has produced very large avalanche activity this week.

The snowpack below the crust is generally strong.

Weather Summary

Monday Night

Cloudy with another 5 cm possible. 40-60 km/h southwest ridgetop wind. Freezing level remains above 1000 m.

Tuesday

Cloudy with up to 10 cm of snow. 30-40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.

Wednesday

A mix of sun and cloud with isolated flurries delivering 5 cm in most areas or higher amounts in localised areas. 10-20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1600 m.

Thursday

Mostly clear skies. 30-40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Cornice failures could trigger very large and destructive avalanches.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Reactive wind slabs likely exist on north and east facing slopes around ridgelines. Small wind slabs could step down to deeper weak layers producing very large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 12th, 2024 4:00PM