Northwest Inland

Watch for signs of instability such as whumpfing. Several weak layers exist in the snowpack and human-triggered avalanches are possible.

On Thursday a large (size 2.5) naturally triggered avalanche was reported in the Ashman area. On Tuesday, a small (size 1) skier-triggered wind slab avalanche was reported in northeast-facing, treeline terrain near Hudson Bay Mountain. Whumpfing been experienced by backcountry users in the Babines, Grizzly Plateau, and Hudson Bay Mountain recently. The whumpfing has been occurring mainly because of the surface hoar layers described in the snowpack summary.

15-20 cm of recent snowfall has been blown around forming new wind slabs on mostly northwest through east-facing slopes at ridgetops. Southerly faces in the alpine are scoured down to the ground or an early-season crust. In most areas, two or more preserved surface hoar layers can be found buried between 35 cm and 80 cm deep. They appear to be most prominent at treeline and below but have been observed in some alpine locations as well.Snowpack depths at treeline are variable across the region with generally deeper amounts (~150cm) in the western part and shallower (~80cm) in the eastern part.Avalanches are currently not a concern below 1100 m elevation as there is not enough snow.

Thurs Night

Cloudy, 2 cm of snow expected. southeasterly 30 km/h winds. Freezing level up to 1200m and treeline temperatures around -2 °C.

Friday

Cloudy, 1cm of new snow with a chance of freezing rain. Winds 30 km/h easterly, Freezing level up to 1200 m. Treeline high of -2 °C.

Cloudy, 5 cm of snow (possibly rain at elevations below 1100 m) expected. 20 km/h southeasterly wind. Freezing level 1250m. Treeline high around -0°C.

Mix of sun and cloud, no precipitation. 30 km/h southwest winds. Freezing level falling to 500 m. Treeline high of -5 °C.

More details can be found in the Mountain Weather Forecast.

• Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.