Avalanche Forecast

Archived

Feb 21st, 2025–Feb 22nd, 2025

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

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.

Choose mellow, low consequence terrain during the storm. The heaviest snowfall is expected around Stewart.

If your area gets less than 30 cm of snow, lower the danger one level.

Confidence

Moderate

Avalanche Summary

On Friday, north of Stewart, explosives avalanche control produced several small (size 1.5), widely propagating avalanches on steep cutbanks.

Looking forward to Saturday, natural and human triggered avalanches will be likely in areas that are seeing rapid loading from new snow and wind.

Snowpack Summary

By Saturday afternoon, 25 to 50 cm of recent storm snow may have fallen with southerly wind forming deeper deposits on northerly aspects. This recent snow will overlie a variety of surfaces including a layer of surface hoar in sheltered terrain and wind-affected snow or a crust in exposed terrain.

In sheltered terrain, a thick layer (40 to 70) cm of faceted snow overlies a crust and layer of surface hoar from late January.

Deeper in the snowpack, another layer of surface hoar was buried near the middle of January.

A weak layer of facets and a crust from early December varies in depth from 100 to 300 cm. This layer remains a concern in this region.

Weather Summary

Friday Night

Cloudy with 5 to 10 cm of snow, 15 to 20 cm around Stewart. 30 to 40 km/h southeast ridgetop wind. Treeline temperature -3 °C.

Saturday

Cloudy with 2 to 5 cm of snow, 10 to 20 cm around Stewart. 30 to 50 km/h south ridgetop wind. Treeline temperature -2 °C.

Sunday

Cloudy with 7-10 cm of snow, up to 20 cm around Stewart. 25 to 35 km/h south or southeast ridgetop wind. Freezing level rising to 1200 m.

Monday

Mostly cloudy with 2-5 cm of snow. 10 to 20 km/h south ridgetop wind. Freezing level falling to valley bottom overnight and rising back to 750 m through the day.

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.
Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.