Avalanche Forecast

On Monday a very large (size 3) storm slab avalanche was triggered by skiers west of Pemberton. The storm slab failed on a rain crust buried 50 to 150cm deep and occurred on a wind-loaded north-facing alpine slope.

Several explosive, natural, and human-triggered avalanches were also reported across the region, up to size 2.5.

Avalanche activity is expected to continue, especially in areas where the new snow has been transported by wind into deeper slabs.

Up to 70 cm of storm snow has accumulated since Saturday in some alpine areas. Much of this snow fell as rain at lower elevations.

A further 10 to 25 cm accompanied by strong to extreme southerly winds is expected on Wednesday, which will likely build touchy cornices and form deeper and more reactive slabs on lee northerly slopes.Additionally, the storm snow may be poorly bonded to an underlying crust, and could result in very large avalanches like the one described in the avalanche summary.

Another buried crust with facets from early December is buried 90 to 160 cm deep at treeline. A layer of surface hoar may also be present in sheltered areas at this same depth.

Tuesday NightCloudy with 2 to 7 cm of snow. 40 to 50 km/h south ridgetop wind. Treeline temperature -4 °C. Freezing level 1000 m.

Wednesday

Cloudy with 10 to 20 cm of snow. 80 km/h south ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.

Thursday

Cloudy with 5 to 10 cm of snow. 25 to 45 km/h variable ridgetop wind. Treeline temperature -3 °C. Freezing level 1000 m.

FridayCloudy. 30 to 40 km/h southeast ridgetop wind. Treeline temperature -3 °C. Freezing level 1000 m.

More details can be found in the Mountain Weather Forecast.

• As the storm slab problem worsens, the easy solution is to choose more conservative terrain.
• Be alert to conditions that change with elevation, aspect, and exposure to wind.
• Be aware of the potential for large avalanches due to a buried crust.