Boundary-Howson-Kispiox-Kitimat-Nass-Ningunsaw-Rupert-Seven Sisters-Shames-Stewart — Bulletin d'avalanche

While details are lacking, a size 3 persistent slab avalanche with a wide propagation was remotely triggered on a north-facing alpine slope on Friday. It appeared to occur on a steep, rocky slope with a thin-to-thick snowpack.On Tuesday, a variety of small to large (size 1-2) natural and explosive triggered avalanches were reported around the region. Wind and Storm slabs in in the alpine, and dry loose in steep terrain.

In the alpine, 20-40 cm of recent snow is settling over crusty surfaces across most terrain, except in high alpine north-facing areas, where dry, wintry snow can still be found. Previous moderate to strong winds (mostly from the southwest) redistributed this loose snow into deeper deposits on leeward slopes.In most places below treeline, the upper snowpack is moist, and possibly even isothermal at low elevations. Several persistent weak layers are buried up to 250 cm deep. While triggering these layers is becoming unlikely, they present a low-probability, high-consequence problem. A cornice fall (large load) may be enough to trigger this slab.