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 21st, 2024–Feb 22nd, 2024

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

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Little change until the wind picks up on Friday, and snow on Saturday. Small isolated wind slabs are still present.

Confidence

Moderate

Avalanche Summary

Sunshine patrol reported triggering very small wind-slabs that were 10cm deep.

A skier triggered a size 1 slab on the far skiers right on the Surprise Pass ski run. It was 30cm deep and 8m wide and ran for 30m.

Snowpack Summary

Suncrust on steep solar aspects and moist snow below 2000m. Isolated wind slabs in the alpine. 10-25 cm of facetted snow over the Feb 3 crust. Persistent weak facet layers remain present in the mid and bottom of the snowpack.

Weather Summary

On Thursday, a mix of sun and cloud across the forecast region as moderate to strong moist, westerly flow continues. Trace accumulations are expected, except up to 2 cm for western-facing aspects. Freezing levels will rise to between 1600 and 1800m in the afternoon. Up to 15cm of snow is expected on the weekend.

For more information be sure to check AvCan's Mountain Weather.

Terrain and Travel Advice

  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

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.