Avalanche Forecast

Issued: Dec 15th, 2013 8:31AM

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

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Monday: Strong westerly flow will prevail over the North Columbia's and Cariboo's  as another Wave of moist Pacific air will move into the interior bringing locally moderate to heavy precipitation and high winds.  Freezing levels will rise during the storm then drop to near valley bottoms.Tuesday: The moist Pacific air will move farther east and south late Tuesday with light precipitation as it leaves the area.  Freezing levels should remain at or close to valley bottoms.Wednesday:  As the Pacific front  moves out of the area , cold arctic air will move in from the north.

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. Moderate to heavy snow fall on top of the recent light snow will continue to add load to 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 with additional 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
The new denser storm and wind slabs are sitting above a weak layer from the cold snap in December. It will take time for these layers to bond. The surface slabs may become easily triggered with increasing snow load.
Minimize exposure during periods of heavy loading from new snow, wind.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Be alert to conditions that change with elevation, precipitation, temperature and wind.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

3 - 4

Persistent Slabs

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 5

Valid until: Dec 16th, 2013 2:00PM

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