Northwest Coastal

Wind slabs are growing while a deeper weakness continues to produce large avalanches. Evaluate the terrain and snowpack carefully before committing to steeper terrain.

High -

WENDESDAY: Flurries starting overnight with 5-10 cm of new snow, strong southwest winds, alpine temperatures around -3 C. THURSDAY: Another 5-10 cm, strong southwest winds, alpine temperatures around -7 C.FRIDAY: Yet another 5-10 cm, sustained strong south winds, alpine temperatures around -4 C.

Reports from Monday indicate the persistent slab problem is alive and well throughout the region. Reports include two size 3 natural avalanches north of Terrace, another size 3 avalanche that was remotely triggered from flat terrain by a snowmobiler north of Stewart, and a few smaller size 1.5-2 persistent slabs also likely triggered by humans. Most of these avalanches occurred on northerly aspects above treeline. One of the large naturals was likely triggered by solar radiation on a south aspect, while the other one by a cornice fall on a northeast aspect. In addition to the ongoing persistent slab problem, the incoming weather pattern is looking to continually build fresh wind slabs.

Expect fresh wind slabs to form in the lee of exposed terrain as unsettled weather brings small amounts of new snow and strong southwest winds. Storm snow from last week is continuing to settle and get redistributed by predominately southerly winds. It may be reactive above a touchy 40 cm deep rain crust. At treeline and above, recent loading has stressed a 1 m deep weak interface composed of facets, crust, and surface hoar from late February. Recent reports suggest this layer is still reactive throughout the region, especially in the north. A non-supportive surface crust has formed over moist or wet snow at 1100 m and below.