Avalanche Forecast

Archived

Dec 13th, 2019–Dec 14th, 2019

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland.

Enough snow may have accumulated to form wind slabs at higher elevations.

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

FRIDAY NIGHT: Cloudy with clear periods, light wind from the northwest, alpine high temperatures around -7 C.

SATURDAY: Mix of sun and cloud, light wind from the northwest, alpine high temperatures around -8 C.

SUNDAY: Mix of sun and cloud, 40 km/h wind from the northwest, alpine high temperatures around -10 C.

MONDAY: Mainly cloudy with flurries, moderate to strong southwest wind, alpine high temperatures around -6 C.

Avalanche Summary

There have been no recent reports of avalanche activity. No significant activity is expected until sufficient snow buries the weak surface hoar layer that formed through the last week.

Snowpack Summary

Light accumulations of snow over the past few days has buried a concerning layer of surface hoar that has formed in areas sheltered from the wind (see photos in this MIN report). 10-20 cm of fresh snow may now sit on this layer. This is likely not enough snow to form a slab above, except in places where there are deeper wind deposits. Reports suggest this layer can be found on all aspects up into treeline. In the alpine, the new snow has buried hard wind slabs and/or sun crusts on south-facing terrain. Snowpack depths are 50-100 cm in alpine areas around Smithers, with depths diminishing rapidly below 1500 m. The relatively thin snowpack has likely caused soft weak snow to form near the ground, however triggering an avalanche on weak basal snow is unlikely under the current conditions.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.