Avalanche Forecast

Archived

Jan 22nd, 2022–Jan 23rd, 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 unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

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, human triggered possible.

Regions

South Coast.

There is a lot of uncertainty as to how the snowpack is going to react to the sustained heat and sun. Loose wet avalanches and cornice failures are expected to become more likely each day. During times of uncertainty, conservative terrain selection is essential.

Confidence

Low - Uncertainty is due to how the snowpack will react to the forecast weather. Uncertainty is due to the limited number of field observations.

Weather Forecast

The region now sits under the warm ridge of high pressure which is expected to persist into next week bringing very high freezing levels and sun.

Saturday night: Clear, moderate NW wind, freezing level 3300 m.

Sunday: A mix of sun and cloud, moderate NW wind, freezing levels around 3000 m dropping to around 2500 m by Sunday night.

Monday: Sunny, light NW wind, freezing levels around 2700 m.

Tuesday: Sunny, light NW wind, freezing levels around 2700 m.

Avalanche Summary

No new avalanche activity have been reported over the last few days but on Thursday, glide cracks were reported to be growing in size, likely from the persistent warm temperatures and rain event.

If you head out into the mountains, please share any observations or photos on the Mountain Information Network.

Snowpack Summary

Warm temperatures are starting to melt a thick crust formed by previous heavy rain saturating the surface snow to mountain top. Below the crust, the snow is moist down 50-100 cm where several old crust are now breaking down. At the highest elevations around Squamish, you may find up to 15 cm of new snow from the recent storm.

Around 150 to 200 cm deep, weak faceted grains may sit above a melt freeze crust that formed during the cold spell in late December. Reports suggest that the snowpack has been bonding well to these layers. The middle and base of the snowpack are strong, consisting of well-bonded snow and various hard melt-freeze crusts.

Terrain and Travel

As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
Cornices become weak with daytime heating or solar exposure.
Even small cornices may have enough mass to be destructive and deadly.

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.

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.