South Rockies

Avalanches are possible on steep, rocky, and wind-affected slopes due to wind slabs and buried weak layers.

On Saturday, numerous large natural slab avalanches were reported in this MIN from Mear Lake. Some of them are suspected to have run on buried weak layers.

Explosive-triggered storm slabs were also reported up to size 2 and shooting cracks showed signs of instability in wind-affected storm snow near Castle.

Small amounts of new snow bring storm totals to around 20 cm. This snow has likely formed wind slabs on lee aspects at treeline and above.

Approximately 40 to 50 cm of snow sits on a crust, except on high-elevation north and east-facing slopes.

A persistent weak layer of surface hoar or facets from late January is buried 50 to 100 cm deep. It is most likely to be triggered on steep, rocky, convex slopes on northerly and easterly aspects at treeline and above.

Sunday night

Cloudy with 1 to 5 cm of snow, light rain below 2000 m. 60 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level rising to 2100 m.

Monday

Cloudy with 1 to 5 cm of snow, light rain below 2100 m. 60 km/h southwest ridgetop winds. Treeline temperature 0 °C. Freezing level 2400 m.

Tuesday

5 to 10 cm of snow above 2100 m overnight then partly clearing skies in the afternoon. 30 km/h southwest ridgetop winds. Treeline temperature +3 °C. Freezing level rising to 2700 m.

Wednesday

Sunny. 10 km/h south ridgetop winds. Treeline temperature +5 °C. Freezing level rising to 3200 m.

More details can be found in the Mountain Weather Forecast.

• Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
• 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.