Avalanche forecast

Northwest Coastal

Apr 27 – 28, 2014Avalanche Canada
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Archived · expired 12 years ago

Avalanche danger

Tue
Wed
Alpine
No rating
Treeline
No rating
Below
No rating
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Highlights

We are no longer issuing danger ratings for this region due to a lack of field data.Please refer to this blog post for more insight into managing the current conditions.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    New wind slabs may develop during the forecast unsettled weather. Wind slabs may not be well bonded to recent melt-freeze crusts. Stiff wind slabs may take a few days to settle and bond.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    Snow may become moist or wet during periods of day time warming. Loose wet snow may release naturally from steep terrain. 

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    3–7
    Deeply buried persistent weak layers continue to be a concern for isolated hard to predict avalanches. Avalanches releasing on these deep layers may be more likely during periods of strong solar radiation, or when there is no overnight freeze.

Weather Forecast

Synopsis: The weather should remain cool and unsettled with winter conditions at higher elevations through Monday. Expect light to moderate precipitation combined with increasing Southwest winds. A ridge of high pressure is forecast to build over the South and Central regions early next week. The ridge should bring warm temperatures and rapidly rising freezing levels, but may not be strong enough in the North to deflect Pacific moisture or clear the cloud from the skies.

Avalanche Summary

Expect new wind slabs and thin storm slabs to develop above recent melt-freeze crusts. These slabs may be easily triggered due to the hard sliding layer of the melt-freeze crust. Daily melt-freeze cycles may be weakening cornices, and they may fall off naturally or be easily triggered. Rain at lower elevations may cause new snow to weaken rapidly and slide out of steep terrain, sometimes gathering mass in constrained terrain features. Deep persistent weak layers may be triggered by rapidly warming temperatures, strong solar radiation, or rain.

Snowpack Summary

The spring snow-pack is comprised of many layers of melt-freeze crusts, thin new snow layers, and stiff wind slabs in the alpine. The snow-pack may be very different depending on elevation, with moist or wet snow in the valleys and near winter conditions in the alpine. The weather can change rapidly at this time of year, and this may result in different types of avalanche problems. Danger is most likely to increase if there is a substantial new snow storm with wind, or if the temperatures increase rapidly with or without sunshine. Our plan is to place a link in the headline that explains general risk scenarios associated with the forecast weather. We will not issue danger ratings for this region due to the lack of data as a result of professional operators closing for the season.

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