Avalanche forecast

Purcells

Feb 4 – 5, 2024Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Small but reactive wind slabs may form as storm snow accumulates on eastern slopes.

Continue to avoid large and consequential terrain while the snowpack cools and strengthens.

Avalanche problems

  • Wind Slabs

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

    Watch for reactivity in wind-affected features where fresh snow has fallen. Although storm totals are small, slabs may slide easily on the crust below.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3

    Multiple weak layers in the top meter of the snowpack remain a concern.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3

    If triggered, this problem will likely be the full depth of the snowpack and could run below treeline. Avoid shallow, rocky start zones.

Confidence

Moderate

Avalanche Summary

We expect wind slab avalanche activity to increase on Sunday with cooler temperatures and fresh snowfall.

Snowpack Summary

By Sunday afternoon storm totals are expected to reach 10 in most areas, with hotspots of up to 20 cm possible on the eastern slopes of the Purcells. This snow accumulates over a crust that varies in thickness and elevation throughout this forecast area. In the Dogtooth Range, this crust thins into the alpine and becomes breakable.

The top 50 cm of snow at treeline is moist with several layers of crusts and facets below. At the base of the snowpack, weak faceted grains and depth hoar is present. While cooler temperatures are expected to help these layers to strengthen we continue to monitor them for signs of reactivity.

Weather Summary

Saturday Night

Cloudy with up to 15 cm of new snow expected, favoring the eastern slopes of the Purcells. Northeast winds 10-30 km/h. Freezing levels around 1500 m, treeline temperatures near -4 °C.

Sunday

Mostly cloudy with up to 5 cm of new snow expected. Freezing levels around 1000 m, treeline temperatures around -8 °C. Easterly winds ease, 10-20 km/h.

Monday

Mostly cloudy with possible flurries. Freezing levels reach 1000 m, treeline temperatures around -8 °C. Southerly winds 10-20 km/h.

Tuesday

Mostly cloudy with possible flurries. Freezing levels reach 1300 m, treeline temperatures around -6 °C Southerly winds 10-20 km/h.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Regions covered