Avalanche Forecast

Archived

Feb 28th, 2024–Feb 29th, 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 avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Sea To Sky, Brandywine, Garibaldi, Homathko, Powell River, Spearhead, Tantalus, Sky Pilot.

Very dangerous avalanche conditions continue at higher elevations. Avoid all avalanche terrain.

Natural and human-triggered avalanche activity remains likely.

Confidence

Moderate

Avalanche Summary

By 4 pm on Wednesday, a widespread natural storm slab avalanche cycle was reported at all elevations up to size 1.5.

On Tuesday, operators in the region continued to observe evidence of numerous natural, large, persistent slab avalanches that likely released during the previous storm.

On Monday, numerous skier remotely triggered persistent slab avalanches were reported up to size 2. These avalanches occurred mainly on north and easterly aspects between 1600 and 2000 m.

Snowpack Summary

30 to 60 cm of storm snow overlies wind-affected surfaces and old wind slabs in exposed areas at all elevations.

Multiple weak layers exist in the upper and mid snowpack. The most concerning weak layer is found down 30 to 100 cm and is composed of a layer of facets or in isolated areas preserved surface hoar above a thick crust. This layer is the culprit of recent remotely-triggered avalanches in low-angle terrain. Professionals are concerned about how this layer will react to the new snow load.

Weather Summary

Wednesday Night

Cloudy with 20 to 30 cm of snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -9 °C. Freezing level drops to valley bottom.

Thursday

Mainly cloudy with 2 to 10 cm of snow. 10 to 25 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing level hovers around 800 m.

Friday

Mainly cloudy with 3 to 10 cm of snow. 25 to 40 km/h south ridgetop wind. Treeline temperature -8 °C. Freezing level hovers around 800 m.

Saturday

Mainly cloudy with 1 to 3 cm of snow. 10 to 30 km/h south ridgetop wind. Treeline temperature -10 °C. Freezing level remains at valley bottom.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.

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.

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.