Avalanche Forecast

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

TUESDAY NIGHT: Cloudy with some isolated flurries, 40 km/h wind from the southwest, alpine temperatures drop to -8 C.

WEDNESDAY: Cloudy with isolated flurries and up to 5 cm of new snow, 40 km/h wind from the west, alpine high temperatures around -5 C.

THURSDAY: 5-10 cm of new snow, 50 km/h wind from the west, alpine high temperatures around -2 C.

FRIDAY: Mostly cloudy, 30 km/h wind from the west, alpine high temperatures around -2 C.

Numerous recent storm slab and persistent slab avalanches have been reported. Explosive control in the Lizard Range over the weekend produced large slab avalanches (size 2-3) at treeline and alpine elevations. The avalanches ran on the both the November and October crust layers 40-100 cm deep. Evidence of natural avalanches with wide propagation have also been reported from the Flathead area.

Fewer avalanches have been reported since the weekend, but the potential for triggering large persistent slab avalanches remains a concern.

30-40 cm of snow from the weekend has been redistributed by the wind to form wind slabs in the alpine and near ridgetops at treeline. Crust layers from November and October can be found 40-100 cm below the surface and have recently produced large avalanches with explosive triggers. While these layers are likely widespread across the terrain, we are uncertain about whether they could also be triggered by humans. Snowpack depths range between 50-100 cm at higher elevations and taper rapidly below treeline.