Avalanche forecast

South Coast Inland

Feb 17, 2017Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The recent storm delivered a storm slab problem to the alpine while saturating lower elevations with rain. Be aware of increasing hazard as you transition to higher elevations.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–4
    A persistent weak layer existing mainly in the north of the region is creating a 'low probabity/high consequence' avalanche problem. The recent storm has added a fresh load above this layer, potentially increasing its likelihood of triggering.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Recently formed storm slabs are expected to remain reactive to human triggering on Friday. Expect hazard to increase along with the depth of new snow as you gain elevation.

Confidence

Moderate -

Weather Forecast

Friday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light to moderate from the south. Freezing level around 1400 metres with alpine temperatures of -6 in the north of the region, -1 in the south. Saturday: Mainly cloudy with isolated flurries and a trace of new snow in the south of the region. Scattered flurries bringing up to 5 cm to the north. Winds light to moderate from the south. Freezing level around 1000 metres with alpine temperatures of -6 in the north of the region, closer to 0 in the south. Sunday: Mainly cloudy with isolated flurries and a trace of new snow in the north of the region. Scattered flurries bringing up to 5 cm to the south. Winds light to moderate from the south. Freezing level around 1200 metres with alpine temperatures around -6 in the north of the region, closer to 0 in the south.

Avalanche Summary

Observations have been limited during the storm, but loose wet point releases were observes running to Size 2 at lower elevations north of Duffey Lake on Wednesday. A number of (presumably large) natural avalanches were also audible in the Bralorne area on Wednesday.

Snowpack Summary

In the Duffey Lake area 25 cm of snow fell on Tuesday through to Thursday morning. Elevations below 1900 m saw mainly rain. In the south (Coquihalla) we had moderate southerly winds and heavy rain above 1600m on Tuesday night (and rain to 2000m during the day Wednesday). This rain (or snow higher up) landed on either wind slabs in the alpine or temperature crusts at treeline and below, especially on east and south aspects. Both of these surfaces will be good sliding layers for future snowfall. The mid-December facets down 130-160 cm remain a concern especially in shallower snowpack areas in the Duffey, Hurley and/or South Chilcotins. These deeper weaknesses warrant renewed attention after considerable warming and extra loading this week. In southern areas (Coquihalla), the lower snowpack is reportedly well settled and stronger than it is to the north.

Regions covered