Avalanche Forecast

Yet another big storm batters the region through the forecast period. Hopefully, Santa will find his way through the wind and the snow!

Wednesday Night: Snow 20 cm. Alpine temperatures -3 and freezing levels 600 m. Ridgetop wind strong to extreme from the southwest. 

Thursday: Heavy snow 20-30 cm. Alpine temperatures -1 with freezing levels 1000 m. Ridgetop wind strong from the southwest.

Friday: Mix of sun and cloud. Alpine temperatures -4 and freezing levels 700 m. Ridgetop wind generally light with strong easterly gusts. 

Saturday: Cloudy with some flurries. Alpine temperatures near -3 and freezing levels 600 m. Ridgetop winds will be light.

On Tuesday reports from the Beaupre sled area and the Nass Valley showed that storm slabs were easily triggered by humans up to size two. Check out the MIN posts here. Reports indicate that the storm slab may be sitting on a weak layer of surface hoar down 40-60 cm which is why the slab is so touchy. Explosive control also showed slabs up to size 2 and natural loose dry sluffing was seen from steeper terrain features. 

Thursday will be a different beast with the new storm. A widespread avalanche cycle is expected. 

Please consider sharing your observations with the Mountain Information Network; even just a photo of your day helps. Thank you to those that have already submitted this winter!

The incoming storm will build new and very reactive storm slabs, especially where the snow has been stiffened by the wind and/ or sit above a recent surface hoar layer buried 40-60 cm down. I'm uncertain how widespread this buried interface is throughout the region besides the Nass Valley. 

A crust that was buried in early December is now down 80-120 cm and counting in the alpine but is closer to the surface at and below treeline elevations. Around this crust are facets and potentially surface hoar in sheltered areas. Storm slabs may step down to this layer.

The early-November crust is buried around 100-200 cm at treeline. This crust may have weak and sugary facets above it in parts of the region. Uncertainty remains about where this layer remains a problem in the region, but it may be localized to the northern half of the region.

• Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
• Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.
• A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.