Avalanche Forecast

Archived

Mar 9th, 2024–Mar 10th, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural and human triggered avalanches likely.

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

South Coast Inland, Birkenhead, Duffey, South Chilcotin, Stein, Taseko.

Very dangerous conditions exist. Manage the uncertainty around buried weak layers by sticking to low-angle non avalanche terrain, avoiding overhead hazard.

Confidence

Low

Avalanche Summary

No new avalanches reported on either Friday or Saturday. On Thursday, a skier trigger avalanche was reported on a north east treeline terrain feature, this avalanche failed on the persistent slab and was nearly 1 meter in depth.

Wednesday a naturally triggered size 1.5 persistent slab avalanche was observed in the alpine on a west aspect.

Snowpack Summary

The storm has as of Saturday afternoon delivered over 25 cm and this new snow overlies a variety of surfaces including surface hoar. Expect strong southwest winds to strip snow from ridgelines and exposed features and deposit new snow into deep pockets in lee aspect terrain. Below this, 50-100 cm of old storm snow continues to settle over a facet/surface hoar/crust layer.

In the mid snowpack, an older problematic combination layer of faceted snow over a thick crust is estimated at 80-140 cm deep. This layer is the primary avalanche concern in the region, continuing to show sensitivity to human triggers and produce concerning snowpack test results. The lower snowpack is well settled and strong.

Weather Summary

Saturday night

Cloudy with snowfall 5-10 cm. 50-80 km/h southwest alpine winds. Treeline temperature -4 °C with freezing levels falling to 900 m.

Sunday

Cloudy with continuing flurries bringing 1-5 cm of new snow,. 30-50 km/h southwest alpine winds. Treeline temperature -1 with freezing level rising to 1500 m.

Monday

Cloudy with continuing flurries bringing 1-5 cm of new snow,. 30-50 km/h south alpine winds, easing. Treeline temperature -3 with freezing level around 1000 m.

Tuesday

Cloudy with continuing flurries bringing 1-5 cm of new snow,. 30-50 km/h south alpine winds, easing. Treeline temperature -3 with freezing level around 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Remote triggering is a concern, watch out for adjacent and overhead slopes.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

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.

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.