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.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Regions

South Coast.

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: Flurries, accumulation 10 to 20 cm, 30-50 km/h southwest wind, treeline temperature -2 C with freezing level at 500 m.

SUNDAY: Sunny with cloudy periods, no precipitation, 20-40 km/h south wind, treeline temperature +5 C with freezing level rising to 2400 m.

MONDAY: Cloudy with scattered showers, accumulation 5 mm, 30-60 km/h southwest wind, treeline temperature 0 C with freezing level going down to 1000 m.

TUESDAY: Rain, heavy at times, accumulation 50-60 mm, 40-70 km/h south wind, treeline temperature +3 C with freezing level at 2000 m.

Avalanche Summary

Although avalanche activity is expected to have decreased on Saturday, it may remain possible for humans to trigger slabs where recent precipitation fell as snow. At lower elevations, any snow that accumulates on Saturday may slide easily on the melt-freeze crust.

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

Snowpack Summary

Rain soaked the snowpack below around 1200 m, which subsequently froze into a hard melt-freeze crust. Above 1200 m, new wind slabs formed from recent snow (50-70 cm) and moderate to strong southwest winds.

Around 100 to 150 cm deep, a thin and hard melt-freeze crust may sit above sugary faceted grains that formed during the cold spell in late December. Reports suggest that the snowpack may be bonding well to these previous surfaces.

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 failure may trigger large avalanches.
Watch for newly formed and reactive wind slabs 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.