Avalanche forecast

Northwest Inland

Jan 25, 2017Avalanche Canada
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Avalanche danger

Wed
Thu
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The deep persistent slab problem is more likely in shallow snowpack areas that have developed a slab over basal facets.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Wind slabs are likely lingering at higher elevations. If triggered, they have the potential to 'step down' and trigger large deep persistent slab avalanches.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3
    Weak sugary snow exists at the bottom of the snowpack, creating the potential for full depth avalanches. This problem may be more likely in shallow snowpack areas near Kispiox and in the north of the region.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Overcast with a chance of flurries and moderate southwest winds overnight and freezing at valley bottoms. Overcast with a couple of cm on Wednesday combined with moderate-strong southwest winds and freezing at valley bottoms. Strong southwest winds combined with 3-5 cm of new snow on Thursday as the freezing level rises to about 1000 metres. Strong southwest winds combined with 5-10 cm of new snow on Friday with freezing levels climbing up to about 1500 metres; uncertainty with the forecast for Friday, this may be limited to the north and west of the region.

Avalanche Summary

A few large avalanches up to size 3.0 were remotely triggered in the Kispiox area on Monday on south thru west aspects at 1700-1800 metres. These avalanches were about 80 cm deep and are suspected to have released on the December 25th surface hoar.

Snowpack Summary

5-20 cm of settled storm snow sits above a widespread rain crust up to about 1300 m. Recent winds have likely formed wind slabs on lee and cross loaded features. Several buried surface hoar layers have been reported 40-80 cm deep and have given variable results in snowpack tests. Many areas have hard slabs in the upper snowpack above weak sugary snow near the ground. Triggering a deep persistent slab above this sugary snow will remain a low probability high consequence scenario for some time.

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