Avalanche Forecast
Issued: Dec 9th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
wlewis,
Avalanche Canada
Storm snow remains primed to human triggers at higher elevations. Continue to be conservative
Strong winds will likely build reactive slabs around ridgelines and mid slope rollovers.
Summary
Confidence
Moderate
Avalanche Summary
Widespread natural activity occurred during the recent storm. Remotely triggered slabs continue to be reported on the surface hoar layer, at treeline and above primarily on north and east facing slopes (however this layer may be reactive on all aspects). A size 1 remote was reported from Glacier National Park yesterday.
Human triggered avalanches are still likely at higher elevations, where slabs sit over the weak surface hoar.
Snowpack Summary
Strong winds will redistribute 10-30 cm of new snow into deeper deposits on north and east facing slopes, this sits over a rain crust that has been observed up to 1800-2100 m throughout this region (treeline and above). A concerning layer of surface hoar is now buried 40-70 cm deep. Many avalanches released in steep terrain and may have destroyed this layer, but it likely still lingers unaffected features.
At lower elevations wet snow has likely refrozen into a hard crust. The middle and base of the snowpack is largely weak and faceted. A hard crust may be found near the ground.
Treeline snowpack depths are variable and generally range between 60 and 100 cm. Snowpack tapers rapidly as you move lower in elevation.
Weather Summary
Saturday Night
Cloudy with southerly winds 40-60 km/h. 5 cm likely overnight.
Sunday
Mostly cloudy, light snowfall continues with up to 5 cm possible. Southwest winds 10-40 km/h,. Freezing levels climb to 1000 m by afternoon, treeline temperatures rise to -4 °C.
Monday
Mostly cloudy, no snowfall expected. Treeline temperatures around -9 °C. Light and variable wind.
Tuesday
Clearing skies with no snowfall expected. Southerly winds, 10-20 km/h.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
Problems
Storm Slabs
Storm snow sits overlies large, weak surface hoar. Triggering is most likely at elevations where the rain crust disappears (above 1800-2100m)
Watch for reactivity in the wind affected storm snow on north and east facing slopes
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 10th, 2023 4:00PM
