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

Jan 25th, 2023–Jan 26th, 2023

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

Regions

North Columbia, South Columbia, Grohman, Esplanade, Jordan, North Selkirk, Shuswap, Badshot-Battle, Central Selkirk, Goat, Gold, Kokanee, North Okanagan, Retallack, Valhalla, Whatshan.

The main concern remains with several buried weak layers that continue to produce high consequence avalanches. Stick to low angle terrain away from any overhead hazard.

Confidence

Moderate

Avalanche Summary

On Monday, a fatal skier-triggered avalanche incident occurred in the Selkirk range near Revelstoke. The avalanche was on an east aspect at 1900 m. It occurred on a steep, unsupported open slope below treeline and failed on a weak layer of surface hoar buried in early January. This was a size 2 with a crown depth of 50 cm.

Numerous natural and human-triggered wind slabs were also observed on Sunday through Tuesday throughout the region, ranging in size from 1.5 to 2.5. One of these avalanches in the south of the region resulted in a partial burial. These avalanches mainly occurred on east and northeast aspects in the alpine and treeline.

High consequence avalanche activity has been ongoing for several weeks. Your best defence is to stay diligent in choosing low-consequence terrain. Stick to slopes that have been heavily trafficked throughout the winter and avoid venturing into untouched zones. Stay disciplined and adjust your expectation for this winter.

Snowpack Summary

New snow continues to gradually accumulate. A layer of surface hoar may be found below 5-15cm of recent snowfall as well as a sun crust on steep solar aspects. At lower elevations, a rain crust exists down 10 to 40cm, with reported elevations extending up to 1700 m around Revelstoke and closer to 2000 m further south.

Two persistent weak layers in the middle of the snowpack may remain reactive to human triggering. They are both surface hoar layers that formed in early January and are typically found 40 to 90 cm deep throughout the region. There are also some deeper facet and surface hoar layers that formed in December, but recent snowpack observations suggest they are strengthening.

The bottom of the snowpack is made up of large weak facets buried in late November, which has caused a deep persistent slab problem for this region.

Weather Summary

Wednesday Night

Mainly cloudy with isolated flurries. Ridge wind northwest 30-60 km/h. Alpine temperature -4 C. Freezing level 1400 m.

Thursday

Mostly cloudy with isolated flurries. Ridge wind northwest 30-60 km/h. Alpine temperature -2 C. Freezing level 1500 m with a temperature inversion possible.

Friday

Mainly cloudy with flurries. Ridge wind northwest 15-40 km/h. Alpine temperature -6 C. Freezing level 500m.

Saturday

Mainly sunny. Ridge wind northeast 30 km/h. Alpine temperature -10 C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be mindful that deep instabilities are still present and have produced recent large avalanches.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

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.

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.