Avalanche Forecast

Moderate - Uncertainty is due to the complexity of the snowpack’s structure.

Monday Night: Cloudy with clear periods, alpine low -12 moderate northwest wind.

Tuesday: Mix of sun and cloud, alpine high -5, moderate southwest wind.

Wednesday: Mainly cloudy with isolated flurries, alpine high -5, moderate west wind increasing to strong overnight.

Thursday: Flurries accumulating 5-10 cm, alpine high -5, strong southwest wind easing to moderate.

On Sunday, neighboring Glacier National Park reported natural storm slab avalanches up to size 2.5 in steep south-facing gullies in the alpine, likely triggered by the first rays of sun to hit the recent storm snow. Natural storm slab activity has been in decline since the end of the storm. However, skier triggered storm slab avalanches up to size 2, and explosive triggered avalanches up to size 3 have been reported as recently as Monday. 

There have also been a few reports of persistent slab avalanches failing on a layer of surface hoar down 80-120 cm at treeline elevations within the past week. At least one of these was remotely triggered (from a distance). 

30-60 cm of new snow from late last week has covered a layer of feathery surface hoar that has been found at all elevations. This surface hoar sits on soft snow that fell shortly before its formation (early last week) and was covered shortly after (mid last week). It may soon settle out, but for now we will continue to watch for it. A thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas (around treeline and below) is now 50-90 cm below the surface.

An additional layer of surface hoar may be found in sheltered areas around treeline down 70-120 cm. In some areas this may sitting on a thin crust. A variety of crusts from late October are buried deeper in the snowpack.