Avalanche forecast

Purcells

Mar 9 – 10, 2024Avalanche Canada
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Archived · expired 3 years ago

Avalanche danger

Mon
Tue
Alpine
4 · High
Treeline
4 · High
Below
4 · High

Highlights

Danger may reach HIGH as mild temperatures and strong sunshine weaken the snowpack. Large natural avalanches may occur.

Choose small, low angle slopes free from overhead hazard.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–1.5

    Winds have picked up and loose snow is available to build fresh and reactive wind slabs. Small wind slabs could step down to deeper weak layers producing very large avalanches.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3.5

    Remote triggering of this layer continues. Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Wet avalanches are more likely on steep, sun affected slopes. Avoid slopes that have moist or wet surface snow.

Confidence

High

Avalanche Summary

Numerous very large natural and explosive-triggered persistent slab avalanches have been reported (size 2 to 3.5) this week. Natural activity appears to be tapering off, and while fewer human triggered avalanches have occurred in the last few days, reports indicate triggering is still very possible - as shown by this remotely triggered avalanche near Golden on Thursday.

The photos below show the type of terrain and typical size for these avalanches.

Snowpack Summary

Surface conditions currently include sun crusts on south facing slopes, lightly wind-affected snow, and settling snow.

A widespread crust that formed in early February is roughly 80-120 cm deep. Weak faceted crystals and surface hoar above this crust are contributing to large avalanches across the province.

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

Weather Summary

Friday Night

Mostly clear skies. 20-40 km/h southwest ridgetop wind. Freezing level drops to valley bottom.

Saturday

Mostly clear skies. 30-50 km/h south ridgetop wind. Freezing levels rise to 1800 m by the afternoon. Treeline temperature -2 °C.

Sunday

Mostly cloudy with 1-5 cm of snow. 20-40 km/h south ridgetop wind. Freezing levels rise to 1500 m by the afternoon. Treeline temperature -4 °C.

Monday

Mostly cloudy. 10-20 km/h south ridgetop wind. Freezing levels rise to 1500 m by the afternoon. Treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Conservative terrain selection is critical, choose only well supported, low consequence lines.
  • Avoid being on or under sun exposed slopes.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.

Regions covered