Avalanche Forecast

Archived

Dec 4th, 2023–Dec 5th, 2023

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

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.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Coquihalla, Harrison-Fraser, Manning, Skagit.

Avalanche danger remains elevated as warm, wet and windy conditions continue throughout Tuesday

Confidence

Low

Avalanche Summary

Despite the lack of reports, we suspect a natural avalanche cycle to occur during the peak of the warming event (Monday night into Tuesday).

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

Snowpack Summary

Approximately 20 to 40 cm of heavy, rain-soaked snow sits over various layers of crusts and old faceted snow and may also overlie isolated pockets of surface hoar in sheltered areas. A thick crust exists at the base of the snowpack at higher elevations.

Treeline snowpack depths in the range of 80-100 cm in the Coquihalla area.

Weather Summary

Monday Night

Cloudy with 40 to 70 mm of rain (potentially wet snow at higher elevations), southwest alpine winds 50 to 70 km/h, treeline temperature 2 °C, freezing level 2700 m.

Tuesday

Cloudy with 30 to 50 mm of a mix of rain and snow, southwest alpine winds 30 to 60 km/h, treeline temperature 1 °C, freezing levels 2100 m and dropping gradually through the day.

Wednesday

Cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -1 °C.

Thursday

Cloudy with 2 to 5 cm of snow, southwest alpine winds 20 to 30 km/h, treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Carefully monitor the bond between the new snow and old surface.
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.