Avalanche Forecast

Issued: Jan 13th, 2014 8:40AM

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 bcorrigan, Avalanche Canada

Summary

Confidence

Fair - Freezing levels are uncertain on Thursday

Weather Forecast

Overnight: Trace of precipitation in the forecast, freezing level drops to valley bottoms overnight. Winds N West gusting mod to strongTuesday: Trace of new snow, winds changing to moderate to strong from the W, freezing levels may rise to 1200m.Wednesday: Light flurries, moderate to strong winds from the west, freezing level to 1000m in parts of the forecast area.Thursday:  No Precipitation in the forecast for Thursday

Avalanche Summary

A widespread natural avalanche cycle has taken place in the past 24 to 48 hours as a result of the large amounts of new snow, rising temperatures and high winds. Wind slabs and shallow snowpack areas are places of highest concern now. The possibility of a relatively small to medium size avalanche stepping down to buried weak layers is high, and may produce a very large and destructive avalanche.

Snowpack Summary

More than 75 cm of recent storm snow overlies a variety of old snow surfaces, ranging from stiff wind slabs to soft facetted snow and/or surface hoar that was buried around Jan. 8th. A rain crust below the 1600m elevation band should now be buried over a metre, and another surface hoar or facet layer is down 160 + cm deep. Snowpack depths vary, but in general around 200cm of snow can be found at tree line with 130 to over 300 cm in the alpine. In some places we're still dealing with a relatively thin snowpack (thanks to a windy early season). The basal facet/crust combo, ( weak sugary snow above and below a crust) near the ground was active in an avalanche cycle last week. This weakness may be difficult to trigger but if triggered, could result in very large, destructive avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Avoid convexities or areas with a thin or variable snowpack.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Persistent Slabs

An icon showing Persistent Slabs
A number of buried persistent weak layers in the mid and lower snowpack could become reactive with heavy loading from snow and wind this weekend. There is potential for large, full-depth avalanches. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 7

Valid until: Jan 14th, 2014 2:00PM

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