Avalanche Forecast

Archived

Feb 29th, 2024–Mar 1st, 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 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

East Kakwa, Kakwa, Pine Pass, Tumbler.

A persistent slab is slowly becoming more reactive as the load above it increases. The best way to manage this problem is to stick to conservative terrain.

Confidence

Moderate

Avalanche Summary

In the neighbouring region, many natural and skier triggered persistent slab avalanches occurred on the facets above the early-February melt-freeze crust described in the Snowpack Summary. They occurred on northerly aspects between 1600 and 2000 m and were 50 to 80 cm thick.

Riders could trigger similar avalanches in the coming days. Persistent slab problems take a while to heal so giving them time is warranted.

Snowpack Summary

30 to 50 cm of recent snow sits on a variety of layers that it may not bond well to, including surface hoar in wind-sheltered terrain, weak facets, or a hard melt-freeze crust on sun-exposed south and west-facing slopes. The wind has likely formed thicker deposits in lee terrain features near ridges.

A thick and hard widespread crust that formed in early February is buried about 50 to 70 cm deep. This crust may have a layer of facets above it, which makes it a troublesome avalanche layer.

The remainder of the snowpack is settled.

Weather Summary

Thursday Night

Mostly cloudy with isolated flurries, 5 cm. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -9 °C.

Friday

Mostly cloudy with sunny breaks and isolated flurries, trace accumulation. 15 to 30 km/h south ridgetop wind. Treeline temperature -13 °C.

Saturday

Mostly cloudy with sunny breaks. 15 to 30 km/h southeast ridgetop wind. Treeline temperature -15 °C.

Sunday

Mix of sun and cloud. 5 to 15 km/h southeast ridgetop wind. Treeline temperature -15 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Use conservative route selection and resist venturing out into complex terrain.
Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.

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.