Avalanche Forecast

Last week, our field team observed several small wind slab avalanches. Check out their latest MIN for more details.

Looking forward to this week, reactive wind slabs are expected to form but concern for large natural and human-triggered deep persistent slab avalanches is at the forefront of our minds. A series of incoming storms will be slowly adding load to a shallow, weak snowpack with multiple layers of concern. It is uncertain when the "tipping point" for large destructive avalanches will be reached but this uncertainty demands conservative and low-consequence terrain selection. Check out this video on incremental loading to learn more.

Please continue to send in your observations through the MIN.

Overnight snowfall has brought 5-15 cm of new snow. The accompanying northwest winds will affect wind-exposed terrain and build fresh wind slabs in lee terrain features. Below the new snow, a sun crust may be found on steep solar aspects.

At lower elevations, a rain crust exists down around 20cm, with reported elevations extending up to 1800 m in the Cariboos and roughly 1200 m in the northern part of the region.

Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. One is a recently buried surface hoar layer found 30 to 60cm deep in sheltered terrain features at treeline and above. At this same depth, a crust exists on steep south-facing slopes. Another layer of facets, crust, and surface hoar was buried around Christmas and is now 50 to 90cm deep. Finally, a layer of large, weak facets buried in November is found near the bottom of the snowpack. This layer is likely most problematic in alpine terrain, where shallower avalanches could scrub down to these basal facets.

Sunday night

Cloudy with increasing snowfall, 5-10 cm of accumulation. Alpine temperatures drop to a low of -10 C. Ridge wind northwest 40-60 km/h. Freezing level at valley bottom.

Monday

Mainly cloudy with continued snowfall, 5 cm of accumulation. Alpine temperatures rise to -7 C. Ridge wind northwest 45-70 km/h. Freezing level rises to 1100 m.

Tuesday

Cloudy with snowfall, 5-10 cm accumulation. Alpine temperatures reach a high of -6 C. Ridge wind northwest 40-60 km/h. Freezing level rises to 1100 m.

Wednesday

Mainly cloudy with snowfall, 5-15 cm of accumulation. Alpine temperatures reach a high of -1 C. Mostly light westerly ridge wind occasionally gusting to 35 km/h. Freezing level rises to 1400 metres.

More details can be found in the Mountain Weather Forecast.

• 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.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
• Uncertainty is best managed through conservative terrain choices at this time.