Avalanche Forecast

On Thursday, a large natural wind slab (size 2) was observed on a steep west alpine slope near Whistler. Explosive control triggered numerous small storm slabs, cornices, and a large (sized 2.5) persistent slab near Whistler. There was also a report of a larger (size 2.5) human-triggered slab in the Spearhead range on Tuesday. This avalanche involved 50 to 100 cm deep persistent weak layers that resulted in wide propagations.

Snow, rain, and wind are reshaping snow surfaces. 15-30 cm of storm snow received since Wednesday night is adding to the 50 to 100 cm of recent wind-affected snow at upper elevations. Treeline and below treeline elevations received more rain, leading to smaller snow totals. The recent snow sits above a layer of poorly bonded crusts and surface hoar, which has shown sensitivity to human triggers and snowpack tests recently. With ongoing rapid changes to the weather, it is uncertain how long this layer will remain a problem.

The lower snowpack is strong and bonded, and total snow depths remain below average.

Thursday Night

Cloudy with up to 2 cm of snow, alpine wind south 30 to 50 km/h, treeline temperature around 0 °C, freezing level around 1700 m.

Friday

Mostly cloudy with up to 2 cm of snow, alpine wind south 30 to 50 km/h, treeline temperature around +2 °C, freezing level climbing to 2200 m.

Saturday

Cloudy with 10-15 cm of snow, alpine wind southwest 50 to 70 km/h, treeline temperature around 0 °C, freezing level around 2000 m lowering to 1500 m by night.

Sunday

Cloudy with sunny periods, no precipitation, alpine wind south 20 km/h, treeline temperature around 0 °C, freezing level around 1400 m.

More details can be found in the Mountain Weather Forecast.

• Give the new snow time to settle and stabilize before pushing into bigger terrain.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.