Avalanche Forecast

Tuesday night: Flurries bringing up to 5 cm. Light easterly wind. Alpine low around -18 °C.

Wednesday: Sunny. Light easterly wind. Alpine temperatures around -14 °C.

Thursday: A mix of sun and cloud. Light to moderate west wind. Alpine temperatures around -10 °C.

Friday: A mix of sun and cloud. Light to moderate west wind. Alpine high around -3 °C. Freezing level rising to 1400 m.

Human triggered avalanche activity has largely tapered off since Friday when several riders triggered storm slabs and loose dry avalanches in the recent snow, including this remotely triggered size 1.5 near Golden.

Solar triggered avalanche activity has been ongoing since the weekend. Countless loose dry avalanches up to size 1.5 have been reported out of steep or extreme terrain throughout the region as well as a few cornice failures up to size 3. Cornices and loose dry avalanches have also served as triggers for slabs on slopes below, including a size 2 reported on Tuesday near Invermere.

Warm temperatures Thursday through Sunday are suspected to have sensitized buried weak layers such that large explosives were able to trigger a few deep avalanches:

• On Sunday explosive work near Panorama triggered size 1.5-2 avalanches on a buried weak layer from mid February up to 40 cm deep. Another round on Monday produced size 1-1.5s on the same layer but showing less propagation. 
• On Friday in the Bugaboos, large explosives triggered several very large avalanches, mostly on northerly aspects in the alpine, including one size 3.5 with a crown 60-200 cm deep.
• Check out this MIN report from Golden of a mysterious size 2 slab avalanche around treeline, suspected to have slid on the mid February weak layer.

Surface snow has likely seen some redistribution and reverse-loading by recent wind in the alpine. These soft wind slabs may sit over recently formed crusts on solar aspects and below 1500 m.

In the south of the region, a well bonded rain crust may be found within the top 30 cm up to 1700 m. A more widespread recently buried weak layer sits 30-60 cm deep throughout the region. It consists of surface hoar in shady, wind-sheltered areas and a sun crust on solar aspects.

An interface from mid-February composed of sun crust and/or surface hoar is now 30-90 cm deep. Explosive work near Invermere (where it is less than 60 cm deep) on Sunday confirmed that this layer can still be triggered by large loads.

A layer of surface hoar from late January has not produced recent avalanche activity but crystals can still be identified 40-50 cm deep near Golden.

• Avoid exposure to slopes that have cornices overhead.
• Recent new snow may be hiding windslabs that were easily visible before the snow fell.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.