Avalanche Forecast

Issued: Dec 11th, 2013 7:47AM

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

triley, Avalanche Canada

Cariboos.

Avalanche danger is increasing as the Pacific storm brings snow and wind to the Northern Interior.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Overnight and Thursday: Pacific moisture is forecast to collide with the remnants of the cold air over the interior bringing 10-20 cms of dry snow. Freezing level should remain at valley bottoms and winds should be moderate from the Southwest.Friday: Continued light to moderate precipitation bringing another 5-15 cms of dry snow.Saturday: Heavy snowfall combined with strong Southwest winds and freezing levels rising to 1500 metres.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

A new storm is forecast to add moderate new snow amounts above the dry cold surface snow that recently buried the very cold and facetted snow that was on the surface during the arctic outbreak. There is a great deal of variation in the snowpack with respect to elevation and exposure to winds. Shallow snowpack areas may be weak and facetted, and may not support the additional load of storm snow. The old storm snow (~30-50cm) overlies the late-November interface which typically consists of sun crusts on steep south facing slopes and surface hoar in sheltered areas. 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 we get additional snow, expect this interface to become more reactive.

Problems

Storm Slabs

The new storm slab is developing as the Pacific moisture is pushed inland from the North Coast. Expect this storm slab to become more reactive when temperatures and freezing levels rise.

Be cautious as you transition into wind affected terrain.>Minimize exposure during periods of heavy loading from new snow, wind.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

The dry cold new snow is slowly adding to the load above this buried weak layer. This layer may become reactive when temperatures and freezing levels rise.

Avoid convexities or areas with a thin or variable snowpack.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Dec 12th, 2013 2:00PM