Avalanche Forecast

Archived

Jan 13th, 2024–Jan 14th, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Blue River, Clearwater, Premier, Clemina, Esplanade, North Monashee, North Selkirk.

Large natural and rider triggered avalanches are still a concern, carefully evaluate slopes for signs of instability and be mindful of large slopes overhead.

Confidence

Moderate

Avalanche Summary

On Friday, a few large natural avalanches to size 3 on south and east aspects in the alpine were reported. Thursday, multiple large explosive controlled avalanches to size 3 were reported in the region that had impressive propagation. Wednesday, avalanche reports documented a natural storm slab cycle averaging size 1-2, with a few size 2.5 avalanches.

Snowpack Summary

Roughly 30-40 cm of new snow fell in the region on Monday and Tuesday. It buried moderately wind-affected snow in exposed areas at higher elevations and otherwise added to about 50 cm of recent storm snow. All this snow overlies a variety of old surfaces, but sheltered terrain where it may overlie preserved surface hoar, is the most concerning. Below 1600m a crust is present beneath the storm snow.

Two additional surface hoar layers in the top 2 m of the snowpack are diminishing in importance. The deeper of the two likely has a robust crust above it, below treeline. The depth of the snowpack varies greatly throughout the region and weak basal facets are present at the base of the snowpack.

Weather Summary

Saturday night

Partly cloudy. Variable alpine wind 10-40 km/h. Treeline temperature -34 °C.

Sunday

Mostly sunny. Northwest alpine wind 10-40 km/h. Treeline temperature -28 °C.

Monday

Mix of sun and cloud. Southwest alpine wind 10-60 km/h. Treeline temperature -23 °C.

Tuesday

Mostly cloudy. Southeast alpine wind 10-30 km/h. Treeline temperature -20 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.

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.

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.