Avalanche Forecast

Issued: Dec 2nd, 2014 8:29AM

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

jlammers, Avalanche Canada

Cariboos.

Wind slabs are adding to the complexity of the avalanche scenario. Conservative terrain selection remains critical.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

A ridge of high pressure will maintain mainly dry conditions for Wednesday and Thursday. For both days, expect a mix of sun and cloud with very light flurries and alpine temperatures of about -9. Winds should be light to moderate from the northwest on Wednesday switching to light and southwesterly by Thursday. A moist and warm southwest flow will bring snowfall to the region late Friday with freezing levels creeping up to about 1400m.

Avalanche Summary

We haven't had any new reports of avalanche activity. This may speak more to a lack of observations rather than actual conditions.If you have any observations, please send them to forecaster@avalanche.ca.

Snowpack Summary

Approximately 100cm of recent storm snow sits on weak crystals which formed throughout early and mid-November. These weak crystals include facets on a hard rain crust, and surface hoar (which may also sit on a crust on steep southerly slopes). Snowpack data from the Cariboo region is very limited at the moment, but I expect these layers are reacting similarly to the North Selkirk/Monashees because the formation conditions were generally the same. Recent snowpack tests suggest these layers can still be human triggered, and if triggered, are capable of producing wide propagations and large avalanches. Recent variable winds may have redistributed surface snow creating dense wind slabs in exposed terrain.

Problems

Persistent Slabs

Up to 100cm of recent snow overlies weak crystals which are most reactive at higher elevations. Triggering may have become less likely; however, avalanches on this layer would be large and destructive

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>Conditions may have improved, but be mindful that deep instabilities are still present.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

Reports of strong northwest winds suggest wind slabs likely exist in exposed terrain. Due to the abnormal wind pattern, these wind slabs may catch skiers and riders by surprise.

Avoid travelling in areas that have been reverse loaded by winds.>Be cautious as you transition into wind affected terrain.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 3rd, 2014 2:00PM