Avalanche Forecast

Archived

Jan 26th, 2023–Jan 27th, 2023

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

Northwest Inland, Kispiox, Microwave-Sinclair, Ningunsaw, South Bulkley, South Bulkley, Telkwa.

Uncertainty remains with buried weak layers. Avoid high-consequence avalanche terrain and use caution traveling in wind-loaded, shallow, rocky start zones.

Confidence

Moderate

Avalanche Summary

An avalanche cycle likely occurred Wednesday, with rain, snow, and high winds. Both loose wet and wind slab releases have been reported in neighboring regions. While it is suspected some of the avalanche activity may have stepped down to deeper weak layers.

Snowpack Summary

At higher elevations, above roughly 2000 m, new snow has been redistributed by strong southwest winds. At lower elevations expect to find a widespread rain crust on the surface or moist, saturated snow at low elevations that are still experiencing above-freezing temperatures.

Several persistent weak layers may be found in the top meter of the snowpack. Most prominently, a layer of surface hoar buried in early January is now 20-50 cm deep and is reactive to skier traffic. A weak layer of facets and/or surface hoar buried in late December is now down 70-110 cm.

In the north of the region, the lower-depth snowpack remains weak and heavily faceted.

Weather Summary

Thursday night

Cloudy with isolated flurries and trace accumulation. Treeline temperatures -5 to -10 C. Moderate to strong west alpine winds. Freezing levels 1000 m.

Friday

Mostly sunny, with no precipitation. Treeline temperatures -5 to -10 C. Light to moderate north alpine winds. Freezing levels 700 m.

Saturday

Sunny, with no precipitation. Treeline temperatures -10 to -20 C. Light to moderate east alpine winds.

Sunday

Sunny, with no precipitation. Treeline temperatures -10 to -15 C. Light north alpine winds.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Extra caution for areas experiencing rapidly warming temperatures for the first time.
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.
Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.

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.

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.