Avalanche forecast

South Coast

Jan 12 – 13, 2014Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Weather patterns are divided across the the region: a clearing trend is forecast for the north, continued precipitation is expected on the Coquilhalla. Avalanche danger will be locally higher in areas that continue to receive heavy snowfall and wind.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–5
    Storm slabs will continue to develop with the ongoing snowfall on in the south of the region. In all areas watch for large and reactive slabs in wind loaded north and east facing terrain at and above treeline.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–6
    On the surface things are looking more "normal" but remember that in places the new snow is sitting on a weak and thin midpack particulary in the north.  Avoid slopes that were shallow and rocky before this last storm

Confidence

Fair

Weather Forecast

The north of the region will see a clearing trend over the next couple of days while moderate snowfall will continue through tomorrow in the Coquihalla.Tonight and Monday: Moderate snow locally in the south, dry in the north / Winds moderate to strong westerly / Freezing level 1300mTuesday: Cloudy / Winds moderate to strong westerly / Freezing levels to rise as high as 2500m.Wednesday: Cloudy / Winds light westerly / Freezing levels 2500m

Avalanche Summary

We have receive reports of a a widespread natural avalanche cycle with numerous large to very avalanches. Some reports indicate isolated avalanches are failing down on the old facet layer just above the ground.

Snowpack Summary

While the storm has passed in the North, local snowfall continues in the Coquihalla.The weekends storm clobbered the region with between 80-100cm of new snow now. Sustained moderate to strong south to southwest winds have created thick and reactive winds slabs. In the north of the region, the storm snow fell onto a week layer of surface hoar from earlier in the month. In areas with a shallow or rocky snowpack facets exist immediately above the ground. Although from the surface things are starting to look more normal for the coast, it is important to remember that the storm snow is sitting on a thin and weak midpack. The "wait 48 hours and you're good" Coastal mantra does not apply as these conditions are likely to persist for some time.These persistent weak layers do not seem to be as prevalent in the south where the early season snowpack was deeper and less affected by early December's cold temperatures.Snowpack depths at treeline range from 150-250 cm in the south of the region, and from 90- 150 cm in the north of the region. In glaciated terrain open and poorly bridged crevasses are everywhere although they are now hiding under a meter of unsupportive storm snow.

Regions covered