Avalanche Forecast

Archived

Apr 20th, 2025–Apr 21st, 2025

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.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Microwave-Sinclair, North Bulkley, South Bulkley, South Bulkley, South Bulkley, Telkwa.

Recently formed wind slabs may be reactive to human triggering.

Data is very sparse this time of year. During periods of uncertainty, a cautious approach is always recommended.

Confidence

Low

Avalanche Summary

On Saturday morning, a skier triggered a size 1 wind slab on an east aspect at 1800 m. It was 25 cm thick and slid on a melt-freeze crust.

On Thursday, a skier triggered a size 2 wind slab on a NE aspect at 2350 m, which was 10-20 cm thick. Natural wet loose avalanches up to size 2.5 and natural cornice releases were also observed.

Snowpack Summary

A widespread surface crust is expected to have formed following Thursday's warming event. The recent snowfall has been redistributed by wind, and small wind slabs may be found in exposed terrain.

There are two notable weak layers from February and March in the middle of the snowpack. These layers have recently gone dormant and are generally not expected to pose a hazard under the current conditions. However, a heavy trigger like a cornice fall may still have the potential to result in an avalanche on one of these layers.

Weather Summary

Sunday Night

Partly cloudy. 30 to 40 km/h west ridgetop wind. Treeline temperature -6 °C.

Monday

Mostly cloudy. 30 to 40 km/h west ridgetop wind. Treeline temperature -5 °C.

Tuesday

Mostly sunny. 10 to 20 km/h northwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1500 m.

Wednesday

Cloudy. 20 to 30 km/h northwest ridgetop wind. Treeline temperature 1 °C. Freezing level 1800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.

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.