Bulletin d’avalanche

Cariboos

Dec 13 – 14, 2013Avalanche Canada
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Archivé · expiré 13 years ago

Danger d’avalanche

Sun
Mon
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Points saillants

Forecast storm snow, strong winds and warm temperatures will elevate the danger rating to HIGH in the alpine for Saturday.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    3–5
    Continual loading of new snow over a variety of persistent weak layers found in the mid snowpack may eventually wake up these layers. The likelihood will increase if the forecast spike in temperatures holds true.

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely - Very Likely
    Taille
    3–4
    Forecast warm, dense snow will likely create a upside down snowpack scenario with widespread storm slabs. This may be particularly touchy where it overlies buried weak layers; surface hoar or facets. Strong west winds may create touchy wind slabs.

Weather Forecast

Friday night and Saturday: The pacific front makes landfall and spills over into the interior by early Saturday. Moderate to locally heavy snowfall (Bowron Lakes a potential hot spot). Winds strong-extreme westerly, and freezing levels rising to 800m. Possibility of an inversion around 1500m.Sunday: The frontal system will move through the north Saturday night and south on Sunday. Light to moderate precipitation amounts and strong/extreme westerly winds. Freezing level will hover around 1300m.Outlook for Monday: Strong northwesterly flow will prevail over the northern interior and light precipitation is expected.

Avalanche Summary

No new avalanches reported.  The lack of observations likely speaks more to the lack of observations rather than actual conditions.  With forecast snowfall, winds and warm temperatures, a spike in avalanche activity is likely through the weekend.

Snowpack Summary

Snowpack depths are likely to vary across the region. At treeline, the average depths of snow is 120-150cm, seasonably below average.The forecast suggests moderate to heavy amounts of new, warmer and denser snow will fall on top of the recent light snow that continues to add load above various buried weak layers. This combination includes wind slabs, crusts, surface hoar, and facets. Rising temperatures forecast over the next few days are expected to consolidate the storm slab above these buried weak layers. It may be difficult to determine when the slab will become more sensitive to light triggers like skiers and sledders. These weak layers are expected to be persistent, although in many areas the upper slab is not yet stiff enough for slab avalanches. When temperatures rise, and we get additional snow, expect this interface to become more reactive.Digging deeper, in the mid-pack, a couple persistent weak layers (surface hoar and facets) are found which formed in mid and late November. Near the base of the snowpack, a early season rain crust exists. The continuous loading of new snow and the rising temperatures may be enough to wake up these previously dormant layers.

Régions couvertes