Avalanche Forecast
Issued: Dec 5th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
mconlan,
Avalanche Canada
Travel in avalanche terrain is not recommended as an intense storm loads a weak snowpack. The weather is triggering natural avalanches.
Summary
Confidence
High
Avalanche Summary
Many large (size 2) slab avalanches were observed in the region on Tuesday, being triggered by the heavy rain. This trend may continue into Wednesday as the storm continues.
Snowpack Summary
A warm storm is rapidly loading the snowpack with snow at high elevations and rain elsewhere, including a weak and feathery surface hoar layer buried about 20 to 30 cm deep. This weak layer may be associated with a hard melt-freeze crust.
The remainder of the snowpack is weak and faceted.
Snowpack depths are approximately 60 to 80 cm at treeline, which rapidly tapers with lower elevations.
Weather Summary
Tuesday Night
Cloudy with heavy rain or 20 to 40 cm of snow near the mountain tops above 2100 m. Southwest alpine wind 40 km/h. Treeline temperature 2 °C. Freezing level 2300 m.
Wednesday
Cloudy with heavy rain or 15 to 25 cm of snow near the mountain tops above 2000 m. Southwest alpine wind 40 km/h. Treeline temperature 1 °C. Freezing level 2100 m.
Thursday
Cloudy with 20 to 50 cm of snow. Southwest alpine wind 20 to 40 km/h. Treeline temperature -3 °C. Freezing level 1900 m dropping to 1300 m.
Friday
Mostly cloudy with 5 cm of snow. Southwest alpine wind 20 km/h. Treeline temperature -6 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of heavy rain.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Problems
Storm Slabs
Rain and snow are rapidly loading a buried weak layer and forming natural avalanches. The most likely terrain features to release are where the snowpack is sufficiently deep and smooth, which is generally found at higher elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Loose wet avalanches are likely wherever rain soaks the snowpack.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Dec 6th, 2023 4:00PM
