Avalanche forecast

Northwest Inland

Apr 15 – 16, 2015Avalanche Canada
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Avalanche danger

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

Localized solar radiation, snow amounts and wind values may be higher than forecast. Use a conservative approach and watch for signs of instabilities like natural avalanche activity.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–3
    Strong winds have redistributed recent storm snow into wind slabs on leeward slopes. They are especially touchy where they sit on buried facets, surface hoar and/ or crusts. Cornices are large and may weaken with solar radiation.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–5
    Additional snow loading on the mid- March persistent weak layer could bring it back to life. Smaller storm slab avalanches may step down to this layer, initiating large and destructive avalanches.

Confidence

Poor - Due to the number of field observations

Weather Forecast

The current wintery weather pattern continues as a pair of fronts hits the North Coast region bringing strong winds and more precipitation. On Thursday, 5-10 mm of precipitation is expected with moderate SW winds and freezing levels rising to 900 m. Friday will see a mix of sun and cloud, 3-5 mm and light ridgetop winds. The weather pattern will start to change as an upper ridge settles in for the later part of the weekend. Saturday will see mostly cloudy skies and warmer temperatures as freezing levels rise to 2200 m. For the long range, the ridge dominates the province through the weekend and will remain stationary until Wednesday bringing warm air and clear, sunny skies.

Avalanche Summary

No new avalanche observations have been reported. On Thursday, touchy wind slabs and storm slabs are likely, especially in areas that receive higher snowfall amounts or localized intense solar radiation.

Snowpack Summary

Recent storm snow has likely formed touchy storm slabs. Strong westerly winds have redistributed this new snow and has formed wind slabs on leeward slopes and behind terrain features. The lack of bond between the new wind slabs and storm slabs over the older snow surfaces buried on April 9 th (surface hoar, crusts and facets) are the primary concern. The March 25th surface hoar / crust layer is reportedly unreactive, however; with the new load of wind and snow this should remain on your radar as it may re-awaken, initiating very-large and destructive avalanches. Large ripe cornices are also of concern and will be a problem with additional loading, especially when the sun shines through with rising freezing levels.

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