Avalanche Forecast

Archived

Dec 4th, 2023–Dec 5th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

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.

Below Treeline

Natural avalanches unlikely.

Regions

Sea To Sky, South Coast, Brandywine, Garibaldi, Homathko, Powell River, Spearhead, Tantalus, North Shore, Sasquatch, Sasquatch, Sky Pilot, Tetrahedron.

Exercise caution and allow adequate time for the snowpack to stabilize following heavy overnight rain and/or snow

Confidence

Moderate

Avalanche Summary

Natural and remotely triggered avalanches in the Whistler area have been reported over the weekend. As well as numerous reports of shooting cracks and whumffs.

We anticipate a widespread natural avalanche cycle to occur Monday night during peak warming and precipitation.

If you're heading out in the backcountry, please consider sharing any observations on the Mountain Information Network

Snowpack Summary

20 to 50 cm of heavy, rain-soaked snow sits over a variable combination of crusts, facets, and surface hoar. These layers will remain a concern in areas where the recent rainwater has not penetrated to the depth of the layer of concern. The snow line has likely crept up as rains have washed away lower elevations.

Weather Summary

Monday Night

Cloudy with 40 to 80 mm of rain, potentially transitioning to snow at higher elevations by morning, southwest alpine winds 60 to 80 km/h, treeline temperature 5 °C and freezing levels 2500 m.

Tuesday

Cloudy with 5 to 15 cm at higher elevations, southwest alpine winds 40 to 60 km/h, treeline temperature 0 °C and freezing levels 1600 m, gradually dropping through the day.

Wednesday

Mostly cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -2 °C.

Thursday

Mostly cloudy with a chance of flurries in coastal regions, northwest alpine winds 10 to 30 km/h, treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
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

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.