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 23rd, 2024–Feb 24th, 2024

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

Purcells, Dogtooth, East Purcell.

Carefully assess steep, rocky, and wind-affected slopes where triggering a slab avalanche is most likely.

Confidence

High

Avalanche Summary

Several naturally, skier, or explosive-triggered storm and wind slab avalanches have been reported over the last couple of days. Avalanches occurred in treeline and alpine terrain on a variety of aspects up to size 2.

A couple of cornice failures have been reported during periods of strong sun.

Snowpack Summary

Approximately 5 to 15 cm of recent snow has buried a variety of old surfaces. Including old wind-affected surfaces in exposed terrain, surface hoar or faceted snow in sheltered terrain, and sun crusts on south-facing slopes.

A widespread crust formed in early February is buried by roughly 20 to 50 cm of snow. This crust may be less prominent or not exist at high alpine elevations.

The mid and lower snowpack is largely faceted with depth hoar and a crust found at the bottom of the snowpack in many areas.

Weather Summary

Friday Night

Mostly cloudy with 0 to 3 cm of snow. 20 to 40 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level 1500 m.

Saturday

Mostly cloudy with 0 to 5 cm of snow. 20 to 40 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level 1500 m.

Sunday

Mostly cloudy with 0 to 5 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 1500 m.

Monday

Mix of sun and cloud with 0 to 2 cm of snow. 10 to 20 km/h west ridgetop wind. Treeline temperature -12 °C. Freezing level at valley bottoms.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

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.