Kitimat

Cold dry snow persists at high northerly elevations, this is also where persistent weak layers are most likely to be reactive.

A significant avalanche cycle occurred last weekend, with very large slab avalanches (up to size 4) failing on multiple persistent weak layers. On Sunday, skiers remotely triggered a size 3 persistent slab near Shames (see photo). Reports of large avalanches to size 3 continued Tuesday through Thursday, likely triggered by warm temperatures or solar input.

A melt-freeze crust has formed on most surfaces. Dry snow persists on northerly aspects at upper elevations.

Where a strong surface crust is found, we expect that triggering deeper instabilities is trending unlike. However, three persistent weak layers remain notable in the snowpack and have been responsible for recent large avalanches. Surface hoar that formed in mid-March can be found 50 to 100 cm below the snow surface. Below this, another layer of surface hoar that formed in early March can be found at a depth of 100 to 150 cm. Additionally, a layer of facets, surface hoar, and/or a crust from mid-February is buried 100 to 200 cm deep.

Friday Night

Increasing clouds. 30 to 40 km/h southeast ridgetop wind. Treeline temperature -10 °C.

Saturday

Mix of sun and cloud, possible convective squalls. 30 to 60 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.

Sunday

Mostly sunny. 15 to 30 km/h southwest ridgetop wind. Treeline temperature +3 °C. Freezing level 1500 m.

Monday

Sunny. 5 to 15 km/h southwest ridgetop wind. Treeline temperature +6 °C. Freezing level 1900 m.

More details can be found in the Mountain Weather Forecast.

• Be aware of the potential for large avalanches due to buried weak layers.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
• Back off slopes as the surface becomes moist or wet with rising temperatures.
• Make conservative terrain choices and avoid overhead hazard.