Avalanche Forecast

Moderate

Riders triggered wind slabs in leeward terrain primarily in upper treeline and alpine elevations over the weekend. Most of these wind slabs likely occurred within the weekend's storm snow.

On Friday, a large avalanche was triggered by riders, likely releasing on the weak layer described in the Snowpack Summary. See this MIN for details and photos, highlighting the propagation potential and high consequence nature of this layer.

Looking forward, strong wind will continue to build new wind slabs in lee terrain features, which will likely remain triggerable by riders in the coming days. It also remains possible that riders could trigger a persistent slab avalanche, where the layer exists.

Strong southwest wind is forecast for Tuesday, which will redistribute the 20 to 30 cm of snow from the weekend and form wind slabs. The snow surface may remain soft in wind-sheltered terrain. This snow overlies old and hard wind slabs in wind-exposed terrain. A hard melt-freeze crust that extends up to about 1700 m is around 50 cm deep.

A weak layer of surface hoar and facets may be buried about 50 to 100 cm deep on north to east aspects in alpine and upper treeline elevations. The layer may rest on a harder melt-freeze crust. Where preserved, this layer has shown to have very high propagation potential and capable of producing large avalanches hundreds of metres wide.

Monday Night

Mostly cloudy with light snowfall, accumulation 1 to 3 cm, 20 to 30 km/h southwest wind, treeline temperature -11 °C.

Tuesday

Cloudy with light snowfall, accumulation 1 to 3 cm, 40 to 50 km/h southwest wind, treeline temperature -11 °C.

Cloudy with snowfall then clearing, accumulation 5 cm, 40 to 60 km/h southwest wind, treeline temperature -8 °C.

Mix of sun and cloud with no precipitation, 30 to 40 km/h southwest wind, treeline temperature -8 °C.

More details can be found in the Mountain Weather Forecast.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Wind slabs are most reactive during their formation.
• Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
• The best and safest riding will be on slopes that have soft snow without any slab properties.