Avalanche Forecast

Archived

Jan 8th, 2022–Jan 9th, 2022

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Regions

Vancouver Island.

Freezing level rising and temperature warming will increase the avalanche danger thoughout the day. Large cornices may become weak and easy to trigger.

Confidence

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

Weather Forecast

The freezing levels will rise significantly to over 2000 metres on Sunday but with no precipitation forecast.

SATURDAY NIGHT: Cloudy with flurries, accumulation 5 to 10 cm, 40-50 km/h southwest wind, treeline temperature -2 C with freezing level rising to 900 m.

SUNDAY: A mix of sun and cloud, no precipitation, 50-70 km/h south wind, treeline temperature 0 C with freezing level rising to 2400 m.

MONDAY: Cloudy with snow and rain, accumulation 10 to 20 cm above 1500 m and rain below, 70-90 km/h southwest wind, treeline temperature +2 C.

TUESDAY: Cloudy with snow and rain, accumulation 35 to 60 cm above 1500 m and rain below, 60-80 km/h southwest wind, treeline temperature +3 C.

Avalanche Summary

Several wind slab avalanches were triggered naturally, by riders, and explosives in the last few days. They were generally 30 to 40 cm deep, on north aspects, and at treeline elevations. These slabs may still be triggerable naturally or by riders on Sunday. Below 1200 m, small pinwheels were observed out of steep terrain from Thursday night's rain.

We'd appreciate any observations while you are out travelling on the Mountain Information Network.

Snowpack Summary

Wind slabs may still be found in steep, lee terrain features, which formed from recent 40 to 60 cm of snow and strong southeast to southwest wind. The snow surface below about 1200 m consists of a hard melt-freeze crust from recent rain. This overlies 100+ cm of snow that accumulated since January 1, which reports suggest is bonding well to the snowpack.

The middle and base of the snowpack are strong, consisting of well-bonded snow and various hard melt-freeze crusts.

Terrain and Travel

Cornices become weak with daytime heating.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Cornice failures could trigger very large and destructive avalanches.
Be careful as you transition into wind affected terrain.

Problems

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

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.