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

Mar 12th, 2024–Mar 13th, 2024

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

Regions

Purcells, Dogtooth, East Purcell.

Stick to mellow terrain, and avoid travelling in or under large, open slopes.

Avoid thin and rocky start zones, a problematic persistent weak layer continues to haunt us.

Confidence

Moderate

Avalanche Summary

On monday, a couple of rider controlled cornices pulled out small slab avalanches on the slope below. Reactivity to human triggers is expected to continue.

Human triggering of very large persistent slab avalanches continues with a size 2 triggered over the weekend. A notable remotely triggered avalanche occurred near Golden on Thursday. And a fatal avalanche occurred in nearby Kananaskis Country on Sunday, where a similar snowpack structure exists.

Snowpack Summary

15-30 cm of low density snow sits over sun crusts on south facing slopes, wind-affected snow at higher elevations, and small surface hoar crystals on settling snow elsewhere. In wind exposed terrain, new cornices and wind slabs have continued to form.

A widespread crust is buried roughly 80-120 cm deep. Weak faceted crystals and surface hoar above this crust are contributing to large avalanches across the province and continue to be the primary layer of concern here.

Additionally, the lower snowpack is mostly made up of weak and faceted layers.

Weather Summary

Tuesday Night

Mostly clear. 0-2 cm of snow expected. Light southwest ridgetop wind. Freezing level falls to 900 m. Treeline low around -5 °C.

Wednesday

Mostly cloudy. 0-1 cm of snow expected. Light southwest ridgetop wind. Freezing levels rise to 1700 m. Treeline temperature -3 °C.

Thursday

Sunny. No new snow expected. Light northwest ridgetop wind. Freezing level at valley bottom overnight, rising to 1800 m. Treeline temperature -3°C.

Friday

Mostly sunny. No new snow expected. Light northwest ridgetop wind. Freezing level at valley bottom overnight, rising to 2900 m. Treeline temperature 3 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Avoid avalanche terrain during periods of strong sun.

Problems

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.

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.