Avalanche forecast

South Rockies

Mar 29 – 31, 2020Avalanche Canada
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Archived · expired 7 years ago

Avalanche danger

Tue
Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

This forecast lacks field observations and has lots of uncertainty. This will be the last avalanche forecast of the season. Reactive wind slabs remain the primary concern, especially around ridge features and wind loaded terrain.

Avalanche problems

  • Wind Slabs

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

    Steady winds continue to impact loose, dry snow. The most reactive deposits will be on leeward slopes, particularly near ridgetop.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2

    Rising freezing levels and precipitation may trigger snow shedding from steep slopes.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2.5–3.5

    Weak snow at the bottom of the snowpack hasn't gone away. Evidence of deep persistent slab avalanches has been focused in the Sparwood-Elkford area over the past month. Human triggering is most likely around steep, rocky terrain features or anywhere the snowpack is thin and weak. A failing cornice could initiate a deep persistent slab when it impacts the slope below.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Saturday night: Cloudy with isolated flurries, trace to 5 cm. Alpine low temperature -6 C. Moderate to strong southwest wind. Freezing level to valley bottom.

Sunday: Cloudy with scattered flurries, trace to 10 cm. Alpine high temperature -1 C. Moderate gusting to strong southwest wind. Freezing level 1900 m.

Monday: Flurries, 5-15 cm. Alpine high temperature -6 C. Moderate gusty southwest wind. Freezing level 1700 m and dropping.

Tuesday: Cloudy with scattered flurries, 5-10 cm. Alpine high temperature -10 C. Light east wind. Freezing level valley bottom.

Avalanche Summary

We have very limited field observations at this time. There have be no new avalanches reported in the region.

Snowpack Summary

Recent snow has been impacted by wind and warm temperatures. Cold, dry snow persists at higher elevations and consists of a variety of wind affected surfaces and a crust on sun-exposed slopes. A crust is on steep solar slopes and below tree line. 

A layer of faceted grains down 40-80 cm overly a melt-freeze crust from early February. The base of the snowpack contains basal facets that are most prominent in shallow, rocky start zones.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Regions covered