Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 12th, 2024–Mar 13th, 2024

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.

Regions

Vancouver Island, East Island, North Island, South Island, West Island.

Use careful routefinding to work around areas of wind-loaded snow. The weak layer under our storm snow produced large avalanches during the storm and could still react to a human trigger.

Confidence

Moderate

Avalanche Summary

On Sunday, a sledder accidentally triggered a size 2.5 wind slab avalanche on a west aspect at 1580 m on Mt Beadnell, commonly referred to as the Adrian riding area. This resulted in a critical burial, serious injuries, and helicopter evacuation.

There is some uncertainty around how much longer the interface below our massive storm snow will persist as a weak layer. Smaller wind slabs formed with new snow are meanwhile likely to trigger and may produce step-down avalanches.

Snowpack Summary

Around 20 cm of new snow overnight Monday brought 4 - day storm totals to 80 to 150 cm. Strong southerly ridgetop winds have been creating variable surfaces in exposed areas and built deep deposits in lee features at alpine and treeline.

The new snow sits over a layer of softer, faceted snow which itself overlies a crust on all but high north aspects. Large surface hoar grains have been observed just below the storm snow in the Mt Cain area. The bond at this interface is likely improving under the weight of the recent snow but it is not yet reliable. It has produced recent destructive avalanches.

The mid and lower snowpack is generally settled and strong.

Below 1000m the upper snowpack may be moist or wet.

Weather Summary

Tuesday night

Clearing but staying mainly cloudy. 20 to 30 km/h southwest ridgetop wind. Freezing level to 600 m.

Wednesday

Partly cloudy. 10 to 15 km/h southwest ridgetop wind. Treeline high around -1 °C with freezing level to 1300 m.

Thursday

A mix of sun and cloud. 15 to 20 km/h variable ridgetop wind shifting northwest. Treeline high around +5 °C with freezing level shooting to 3300m.

Friday

Mainly sunny. 10-15 km/h north ridgetop wind. Treeline high around +14 °C with freezing level to 3500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

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.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.