Avalanche Forecast

Issued: Mar 15th, 2014 9:48AM

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

Avalanche Canada rbuhler, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

The storm is expected to end on Sunday evening. A ridge of high pressure will build in the wake of the storm system. Dry, sunny conditions are expected for Monday into Tuesday. The next frontal system should reach the south coast on Tuesday night.Sat. Night/Sunday: Snowfall 25-35cm, freezing level am: 1500m pm: 1000m, ridgetop winds 30-50 km/h SW easing during the day.Monday: Mostly sunny, dry conditions, freezing level am: 500m pm: 1000m, ridgetop winds light NWTuesday: A mix of sun and cloud, dry conditions with the possibility of snow in the evening, freezing level am: 500m pm: 1200m, ridgetop winds light W-NW

Avalanche Summary

Limited reports from Saturday suggest avalanche activity was limited to wind loaded features.  More widespread storm slab activity is expected for Saturday night and Sunday as the storm progresses.

Snowpack Summary

The storm snow is sitting on a weak layer consisting of a well developed sun crust on solar aspects and surface hoar on shady, sheltered slopes. At lower elevations, a crust can be expected in most areas. S-SW winds are forming wind slabs on leeward slopes. Below the storm snow, the upper snowpack is generally well settled from the recently warm weather. There are two persistent weak layers which remain a concern but the problem is becoming isolated. Before the storm, the early-March crust/facet layer was down roughly 1m and the early-Feb layer is down 1.5m or more. These layers are typically deep enough that human-triggering is unlikely but smaller avalanches or cornices have the potential to step down to these layers. Freezing levels have been cycling between valley bottom and 1500-2000m, and low elevation terrain saw significant rain last weekend. The snowpack at lower elevations has been generally stable but wet snow or rain may destabilize the upper snowpack.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall and strong winds continue to build storm slabs. Expect stiffer wind slabs in leeward features from strong S-SW wind.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 4

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
There are two deep persistent weak layers of concern within the snowpack. These have been quiet recently but may reactivate with the weight of the new storm snow. Smaller avalanches have the potential to step down to one of these deeper layers.
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.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Mar 16th, 2014 2:00PM

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