Sea To Sky

Storm slabs are sitting on a persistent weak layer that could produce surprisingly large avalanches.

Choose simple, low angle terrain with no overhead hazard.

Moderate

• We are uncertain due to how buried persistent weak layers will react with the forecast weather.
• We are uncertain about forecast snowfall amounts.

On Friday, numerous skier triggered storm slabs up to size 2 were reported in areas that have received more than 30 cm of recent snow.

The avalanches occurred at treeline and above on all aspects. The crown depths were generally 20 to 30 cm.

20 to 40 cm of recent snow and extreme southerly wind have formed reactive storm slabs overlying persistent weak layers.

At treeline and above, this layer is primarily a hard crust with weak facets above and/or below.

In sheltered treeline locations and below, this layer may be a combination of hard crust and/or surface hoar.

Cornices are reported to be large and looming. Be mindful of them overhead or when travelling on ridge tops.

The mid/lower snowpack is generally well settled and strong.

Saturday Night
Cloudy. 15 to 25 cm of snow above 1400 m (rain below). 50 km/h south ridgetop wind. Treeline temperature 1 °C. Freezing level 1700 m.

Sunday
Cloudy. 15 to 25 cm of snow above 1200 m (rain below). 40 km/h south ridgetop wind. Treeline temperature -1 °C. Freezing level 1500 m.

Monday
Cloudy. 15 to 25 cm of snow above 1400 m (rain below). 60 km/h south ridgetop wind. Treeline temperature 1 °C. Freezing level 1700 m.

Tuesday
Mostly cloudy. 50 km/h southwest ridgetop wind. Treeline temperature 4 °C. Freezing level 2300 m.

More details can be found in the Mountain Weather Forecast.

• Use conservative route selection. Choose simple, low angle terrain with no overhead hazard.
• Be aware of the potential for larger than expected storm slabs due to buried surface hoar.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
• Use small, low consequence slopes to test the bond of the new snow.