Avalanche Forecast

Archived

Apr 10th, 2025–Apr 11th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

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.

Dangerous conditions are likely in wind-affected alpine terrain and along ridgelines.

Confidence

Moderate

Avalanche Summary

Natural wind slab avalanches likely occurred during the height of Thursday’s storm, and these slabs will be primed for human triggering on Friday.

Earlier storms this week caused natural avalanches up to size 2.5 across the region. Additionally, a few human-triggered slabs (size 1 to 1.5) were reported, along with cornice falls triggered by explosives.

Snowpack Summary

In the alpine, another 15 to 30 cm of snow on Thursday will bring total amounts from the past few days to a range of 70 cm near the coast (e.g., Squamish) to 20 cm inland (e.g., Chilcotin). This new snow is heavily wind-affected and rests on wet snow and crusts.

At treeline, mixed precipitation has resulted in mostly wet and crusty surfaces.

Lower elevations are melting out quickly.

The snowpack is generally strong and bonded, although dormant weak layers may still exist in shallow inland areas like the Duffey and Chilcotin. These are not a concern at this time.

Weather Summary

Thursday Night

Cloudy with 5 to 20 cm of snow (greatest amounts near coast). 50 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1200 m.

Friday

Cloudy with 0 to 2 cm of snow. 20 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1200 m.

Saturday

Mix of sun and cloud. 20 km/h northwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1500 m.

Sunday

Mix of sun and cloud. 10 km/h west ridgetop wind. Treeline temperature 0 °C. Freezing level 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid freshly wind-loaded terrain features.
Dial back your terrain choices if you are seeing more than 20 cm of new snow.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

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.

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.