Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 17th, 2023–Dec 18th, 2023

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

South Columbia, Shuswap, Badshot-Battle, Goat, Gold, Kokanee, North Okanagan, Retallack, Valhalla, Whatshan.

Start with small slopes, and gather information before entering committing terrain.

Continue to be wary of a buried layer of surface hoar. The crust that was shielding it is getting weaker.

Confidence

Moderate

Avalanche Summary

On the weekend the only reported avalanches were loose in steep terrain, and wind slabs and cornices controlled by explosives. These avalanches were all small.

The surface hoar continues to cause concerning results in snowpack tests, and shows signs of instability like whumpfs and shooting cracks. Despite a lack of avalanche observations, we presume that large, human triggered avalanches are still possible in areas where the crust over it is thin or non-existent.

Snowpack Summary

10-15 cm of recent snow has been redistributed by moderate southwest wind. This sits on old wind slabs, and sun crusts on steeper south aspects, and in areas sheltered from the wind, 5-30 mm surface hoar.

Down 30-50 cm a 5-15 cm thick, frozen crust exists. It has been observed up to 2350 m, but it is starting to break down at treeline and above, where it is thinner. A concerning layer of surface hoar buried in early December is 60-90 cm deep at treeline and above.

The lower snowpack is generally faceted, but is also moist in some areas in the south end of the forecast area.

Average treeline snowpack depths are between 80 and 150 cm. Snowpack depth tapers rapidly with elevation.

Weather Summary

Sunday Night

Mostly clear. No new snow expected. Light southwest ridgetop wind. Treeline high around 2°C with above freezing layer.

Monday

Mostly cloudy. Possible trace of snow expected. Light to moderate south ridgetop wind. Treeline temperature around 2°C with above freezing layer.

Tuesday

Cloudy. 2-5 cm of snow expected. Light to moderate south or southeast ridgetop wind. Treeline temperature around -3°C with alpine temperature inversion.

Wednesday

Cloudy. 5-10 cm of snow expected. Light to moderate southwest ridgetop wind. Treeline temperature around -1°C with alpine temperature inversion.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Use conservative route selection and resist venturing out into complex terrain.
  • Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
  • Approach lee and cross-loaded slopes with caution.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

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.