Avalanche Forecast

Archived

Mar 4th, 2025–Mar 5th, 2025

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 avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Northwest Coastal, Northwest Inland, Boundary, Stewart, Kispiox, Ningunsaw, Ningunsaw, Ningunsaw.

The snowpack remains primed for human triggering.

Stick to conservative terrain and avoid overhead hazard, remote triggering is possible.

Confidence

Moderate

Avalanche Summary

Over the weekend widespread slab avalanches up to size 3.5 was reported. Activity has decreased but the potential for large and destructive avalanches remains.

Explosive control work on Monday produced slabs up to size 3.5 on the February weak layer. Remotely triggered slabs (from humans and vehicles) were also reported to size 3.

Looking forward, natural activity is expected to taper off but human triggering remains a significant concern.

Snowpack Summary

Recent storm snow has been wind affected in exposed terrain. Cornices are large and have recently triggered slab avalanches on the slopes below. South-facing slopes and low elevations hold a surface crust.

Facets, surface hoar (in sheltered terrain), and a crust on solar aspects that all formed during the February drought, are buried 50 to 100 cm deep. This layer has produced large natural and human-triggered avalanches this week.

Deeper in the snowpack, facets and a crust from early December can be found from 100 to 300 cm deep. This layer appears to be dormant but remains an isolated concern in this region.

Weather Summary

Tuesday Night

Partly cloudy. 20 to 30 km/h southeast ridgetop wind. Freezing level drops to valley bottom.

Wednesday

A mix of sun and cloud. 10 to 20 km/h southeast ridgetop wind. Treeline temperatures -4 °C. Freezing level 900 m.

Thursday

A mix of sun and cloud with up to 5 cm of snow possible. 30 to 40 km/h southwest ridgetop wind. Treeline temperatures -4 °C. Freezing level 900 m.

Friday

Cloudy with 10-20 cm of snow. 50 to 70 km/h southwest ridgetop wind. Treeline temperatures -3 °C. Freezing level 1100 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be mindful that deep instabilities are still present in the snowpack.
Conservative terrain selection is critical; choose gentle, low consequence lines.
Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
Cornice failures could trigger large and destructive avalanches.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

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.