Avalanche Forecast

Issued: Mar 8th, 2014 8:08AM

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

Avalanche Canada triley, Avalanche Canada

A warm, wet, and windy storm is expected to result in natural avalanche activity by morning.

Summary

Confidence

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

Weather Forecast

Overnight and Sunday: Strong Southwest winds and heavy precipitation overnight and Sunday morning. Freezing levels around 1800 metres overnight falling in the afternoon to 1000 metres.Monday: Mostly cloudy with light Westerly winds, some flurries and freezing levels rising to 1300 metres during the afternoon.Tuesday: Overnight freezing down to valley bottoms. Clear in the morning with light Westerly winds. Chance of snow in the afternoon as moisture pushed North of the ridge may slide down into the region.

Avalanche Summary

Some natural, skier controlled, and remotely triggered storm slab avalanches have been reported releasing down 30-50 cm. Some of these avalanches have released on buried melt-freeze crusts on Southerly aspects. Expect natural avalanches to continue and to increase in size as the storm slab continues to develop.

Snowpack Summary

In general, about 30-50 cm of storm snow overlies small surface hoar crystals in sheltered areas, a sun crust on solar aspects and wind slabs in exposed terrain. Further snowfall, wind and warming will add to the reactivity and destructive potential of this developing storm slab. There is ongoing concern for a mix of weak surfaces which were buried on February 10th. This persistent interface lies up to a metre below the surface, and includes weak surface hoar, well developed facets and a mix of hard surfaces which remain widespread at all aspects and elevations.  For the most part, the mid and lower snowpack are strong and well consolidated. Weak basal facets exist in some areas, but triggering has now become unlikely.

Problems

Storm Slabs

An icon showing Storm Slabs
The storm slab is expected to continue to develop with forecast new snow and strong Southwest winds. Touchy slab avalanches may result as the storm snow settles into a cohesive slab above the crusts and facets.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Be alert to conditions that change with elevation.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
The early February weak layer may be stubborn to trigger, but long fracture propagations may still result if a large force such as a storm slab in motion or a cornice fall steps down to the persistent weak layer.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Mar 9th, 2014 3:00PM

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