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

Feb 8th, 2023–Feb 9th, 2023

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

Regions

Lizard-Flathead, South Rockies, Flathead, Bull, Elkford East, Elkford West.

New snow falling earlier this week combined with wind will continue to promote wind slab formation.

Confidence

Moderate

Avalanche Summary

On Saturday, east of Fernie, a couple of small to large natural and rider triggered avalanches were reported that involved cornices. See the MIN report for more information.

Natural and rider-triggered (size 1 to 1.5) wind slabs have been recently reported at treeline and alpine elevations. This MIN report from the South Rockies field team is a good example of terrain where wind slabs are more likely to be triggered.

Please continue to share any observations or photos on the Mountain Information Network.

Snowpack Summary

There is 10-20cm of new snow from early this week, which is likely being redistributed into lee terrain in wind exposed areas at upper elevations. This overlies previous wind slabs, or a melt-freeze crust below 1900 m.

Deep weak layers formed early season are slowly gaining strength but are still a concern, especially in steep rocky terrain features where the snowpack is thin.

Weather Summary

Wednesday Night

Mostly cloudy with clear periods. Light to moderate west and southwest ridgetop wind. Treeline temperature around -8 °C. Freezing level at valley bottom.

Thursday

Mix of sun and cloud. Moderate southwest ridgetop wind. Treeline temperature around -4 °C. Freezing level rising to 1400m.

Friday

Mainly cloudy with scattered flurries, accumulation 3-5cm. Moderate to strong southwest ridgetop wind. Treeline temperature around -3 ºC. Freezing level rising to 1500m.

Saturday

Mainly cloudy with isolated flurries. Light to moderate west ridgetop wind. Treeline temperature around -4 ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Approach lee and cross-loaded slopes with caution.
  • Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

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.