Avalanche Forecast

Weather model predictions have changed since yesterday. Forecasted snowfall and wind have decreased. The weather forecast is a bit uncertain as this system moves quickly down the coast and across the province.

Friday Night: Mostly cloudy. 0-7 cm of snow expected. Light to moderate southwest winds, shifting to easterlies. Treeline high around -14 °C. Possible temperature inversion resulting in temperatures above -10 between 1500 and 2000 m.

Saturday: Mostly cloudy in the morning, scattered cloud by the afternoon. 0-5 cm of snow expected. Moderate northeast winds, trending to east at higher elevations. Treeline high around -12 °C, temperature inversion breaking down.

Sunday: Mostly sunny. No new snow expected. Moderate northeast winds. Treeline high around -12 °C.

Monday: Sunny. No new snow expected. Moderate to strong northeast winds. Treeline high around -10 °C. 

Fresh wind slabs in lee features may be reactive to the weight of a rider, especially in sheltered areas, where they may sit on top of weak, feathery, surface hoar crystals. 

Older wind slabs may be found on all aspects due to recent variable winds, and could be harder to trigger, but would produce larger avalanches. 

On Wednesday, one isolated size 2 avalanche was reported in the Skeena valley. It was reported as a glide slab failing on a smooth rock face.

The persistent slab problem appears to generally have stabilized in the south of the region but remains a concern in the north. We are now likely in a low probability/high consequence scenario with the persistent problem. 

On Tuesday, natural wind slabs to size 2 were reported in the north of the region. In the south, explosives were triggering wind slabs to size 2. This MIN report highlights the wind slab problem around Terrace. 

5-15 cm of new snow has likely built thin wind slabs on westerly aspects. This new snow is falling on a surface that was observed to be facets, or surface hoar up to 12 mm. While it may not produce numerous, large avalanches, this layer could prove to be touchy if a rider hits an unsupported spot with a dense enough slab on top of it.

Given the variable nature of the recent wind, buried wind slabs should be expected on all aspects in exposed terrain.

The December 7 persistent weak layer is now typically down 50-70 cm, except for near the immediate coast, where it is closer to 100 cm. This interface may include a crust, facets, and/or surface hoar. This layer appears to be gaining strength through the south of the region but remains a concern for the north of the region. 

A bit deeper in the snowpack is the December 1 crust/facet layer, which generally appears to have stabilized but may still be reactive in isolated areas. 

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Be aware of the potential for large avalanches due to the presence of buried weak layers.
• In times of uncertainty conservative terrain choices are our best defense.
• Dial back your terrain choices if you are seeing more than 20 cm of new snow.