Avalanche Forecast

Issued: Dec 14th, 2013 8:34AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

Avalanche Canada bcorrigan, Avalanche Canada

New storm snow with strong winds will to keep the danger ratings considerable until the next storm arrives.

Summary

Weather Forecast

Sunday: The frontal system will move through the north Saturday night and  continue south on Sunday. Light to locally moderate precipitation amounts and strong westerly winds. Freezing level will rise to around 1300m.Monday: Strong northwesterly flow will prevail over the northern interior with very light or no precipitation, freezing levels will drop to valley bottoms.Tuesday: Another Wave of moist Pacific air will move into the interior for Tuesday bringing moderate to locally heavy precipitation, strong winds and rising temperatures.  Freezing levels should remain at or close to valley bottoms.

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 and into the beginning of next week.

Snowpack Summary

Snowpack levels vary across the region. At treeline, the average snow depth is 120-150cm, and below the season average.Moderate to heavy snow fall on top of the recent light snow will continue to add load above buried weak layers. The  upper snowpack contains wind slabs, crusts, surface hoar, and facets. Rising temperatures forecast over the next few days will consolidate the storm slab above these weak layers. It's 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 withadditional snow, expect these layers to become more reactive.Digging deeper, into the mid-pack, a couple of persistent weak layers (surface hoar and facets) can be found that formed in mid and late November. Near the base of the snowpack, an 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.

Problems

Storm Slabs

An icon showing Storm Slabs
Be alert to conditions that change with elevation, precipitation, temperature and wind.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Minimize exposure during periods of heavy loading from new snow, wind.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

3 - 4

Persistent Slabs

An icon showing Persistent Slabs
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 5

Valid until: Dec 15th, 2013 2:00PM

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