Avalanche Forecast

Issued: Dec 18th, 2013 8:35AM

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

ghelgeson, Avalanche Canada

Cariboos.

Forecasters are operating with limited field data this early in the season. If you have been in the backcountry and have information, we'd love to hear from you. Contact us at:forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: Arctic air begins to creep in over the next few days. The pattern shifts to a NW flow which should deliver small amounts of snow beginning early Friday.Thursday: Freezing Level: Valley Bottom Precip: Trace Wind: Mod, WestFriday: Freezing Level: Valley Bottom Precip: 2/4mm 4/10cm Wind: Moderate, WestSaturday: Freezing Level: 700m Precip: Trace Wind: Light, NW.

Avalanche Summary

No new avalanches in the region have been reported. This is more likely because of lack of observations rather than actual conditions. More westerly regions have reported a dramatic rise in avalanche activity.

Snowpack Summary

Snowpack depths vary widely with reports of up to 180cm at tree line in some parts of the region. The upper snowpack contains storm snow, wind slabs, surface hoar, and facets. Warm temps and as much as 70cm of new snow have combined to form a cohesive slab on top of the surface hoar and facets. It's difficult to determine if the slab is currently reactive to light triggers like skiers and sledders. Deeper in the mid-pack a couple of persistent weak layers (surface hoar and facets) can be found that formed in mid and late November. Near the base of the snowpack an early season rain crust exists.

Problems

Storm Slabs

Moderate winds continue to redistribute storm snow and create fresh windslabs. These windslabs are likely sensitive to human triggering. Watch for these windslabs in open terrain at and above treeline.

Be aware of the potential for wide propagations due to the presence of hard windslabs.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Minimize exposure during periods of heavy loading from new snow, wind.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Persistent Slabs

Persistent weak layers that were created and buried in October & November may be sensitive to human triggering. Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.

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 due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Dec 19th, 2013 2:00PM