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

Apr 13th, 2022–Apr 14th, 2022

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

Regions

Purcells.

Small reactive wind slabs may still be lingering in exposed high elevation terrain. 

Cornices have grown large and may fail under the weight of a human. Give them a wide berth when travelling on ridges and watch for signs that they may be weakening with extended sun exposure. 

Confidence

Moderate - Uncertainty is due to the limited number of field observations. Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Wednesday night: Partly cloudy, light east wind, treeline low around -15 °C.

Thursday: A mix of sun and cloud, light east wind, treeline high around -5 °C.

Friday: A mix of sun and cloud, light variable wind, treeline high around -4 °C.

Saturday: A mix of sun and cloud, light to moderate east wind, treeline high around -3 °C.

Avalanche Summary

On Monday, explosives triggered several cornice releases up to size 2.5 above 2400 m in the western part of the region. A couple of these triggered small slabs on the slopes below. Most notably, one of them triggered a triggered an 80 cm thick slab which was expected to have released on facets which were buried at the end of March. 

Observations are limited this time of year. If you are getting out in the backcountry, please consider contributing to the Mountain Information Network.

Snowpack Summary

10-30 cm of aging storm snow has buried a widespread melt-freeze crust which formed during the major warming event on April 8. Recent moderate to strong winds have redistributed the recent snow forming reactive wind slabs in exposed terrain at higher elevations. The recent wind direction appears to have been variable across the region with mainly southwest wind in the north of the region and mainly northeast wind in the south of the region. 

A thick rain crust with facets above from early December is buried around 100-200 cm deep. Large avalanches were naturally triggered on this layer during the last significant warming event in the western part of the region near the Bugaboos. With the current cold temperatures, avalanche activity on this layer is unlikely. However, we expect it will wake up again with the next major input of warming and sun, or rainfall.

Terrain and Travel

  • Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

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.