Avalanche hazard is decreasing, but a buried persistent weak layer can still produce large, distructive avalanches.
Stubborn wind slabs may lurk around ridges and lee terrain. Check for wind-loaded pockets under convex rolls and in cross-loaded features. Wind slabs may overlie a weak layer of facets and could remain reactive for longer than usual.
Persistent weak layers of facets or crust/facets combinations are buried 100-200 deep, and have recently produced large avalanches. Avoid steep, rocky, and wind-affected areas where triggering these slabs is more likely.
On Wednesday, a widely propagating size 3 natural persistent slab was observed on a southeast alpine face.
On Tuesday, multiple widely propagating natural avalanches were observed in steep terrain. A cornice was also remotely triggered by snowmobilers. Read more in this MIN report.
A very large avalanche resulted in a fatality on March 22 near Mt McDonell. More information can be found here.
Up to 20 cm of low-density snow covers a supportive crust. At ridgeline and exposed terrain, strong winds have left slabs and wind-pressed surfaces. Recent wind slabs have failed naturally and are reactive to ridgers, particularly where they cover a weak layer of crust/facets.
A notable layer of facets or a crust/facet combination is buried 100-200 cm and continues to show reactivity in test profiles. With the depth of this layer, a concern for triggering would be in shallow, thin to thick areas or from a large trigger, such as a cornice fall.
Friday Night
Clear skies. 10 km/h northeast ridgetop wind. Treeline temperature -13 °C.
Saturday
Sunny. 10 km/h northwest ridgetop wind. Treeline temperature -14 °C.
Sunday
Mostly sunny. 10 km/h northwest ridgetop wind. Treeline temperature -14 °C.
Monday
Mostly sunny. 10 km/h southwest ridgetop wind. Treeline temperature -13 °C.
More details can be found in the Mountain Weather Forecast.
