Avalanche Forecast

Archived

Apr 17th, 2025–Apr 18th, 2025

Alpine

Natural avalanches possible, human triggered probable.

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.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Sea To Sky, South Coast Inland, Brandywine, Garibaldi, Homathko, Spearhead, Tantalus, Birkenhead, Duffey, South Chilcotin, Stein, Taseko.

High temperatures will weaken the snowpack, especially if there is no overnight refreeze.

Avoid overhead exposure to cornices, and steep south-facing slopes in the heat of the day.

Confidence

Moderate

Avalanche Summary

Numerous natural loose wet avalanches were reported from all aspects at treeline and above. They all occurred later in the afternoon during the peak of warming, some involving large debris (size 2).

Recent cornice failures were also reported, with some triggering wet avalanches on slopes below.

Expect an increase in avalanche activity with the upcoming warming on Friday.

Snowpack Summary

A typical spring diurnal cycle is underway.

High freezing levels have transformed the surface during the day into moist snow, while cooling at night has formed a crust.

Dry snow may persist only in the highest north-facing terrain.

The snowpack is generally well-settled and strong, although dormant weak layers may still exist in shallow inland areas like the Duffey and Chilcotin.

Sustained high freezing levels with poor overnight recovery have the potential to awaken dormant weak layers.

Lower elevations are melting out rapidly.

Weather Summary

Thursday Night

Clear. 15 to 25 km/h north ridgetop wind. Treeline temperature 3 °C. Freezing level 2500 m.

Friday

Sunny with increasing cloudiness. 15 to 25 km/h southwest ridgetop wind. Treeline temperature 8 °C. Freezing level 3500 m.

Saturday

Cloudy with isolated flurries. 20 to 30 km/h southwest ridgetop wind. Treeline temperature 2 °C. Freezing level lowering to 1800 m.

Sunday

Cloudy with isolated flurries. 10 to 20 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid exposure to overhead hazards when solar radiation is strong.
Avoid travelling on slopes below cornices.
Back off slopes as the surface becomes moist or wet with rising temperatures.
Triggering deep layers is more likely if the snow surface didn't freeze overnight.

Problems

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.

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.