Avalanche Forecast

Issued: Dec 30th, 2013 8:47AM

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

rbuhler, Avalanche Canada

Cariboos.

Summary

Confidence

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

Weather Forecast

A weak ridge of high pressure will bring unsettled conditions to the interior regions on Tuesday and Wednesday. The next frontal system is expected to hit the north coast on Wednesday night or Thursday morning and should bring moderate amounts of precipitation to the Cariboos by Thursday afternoon.Tuesday: Mostly cloudy, generally dry conditions but light flurries possible, treeline temperatures around -5C, light to moderate W-NW winds.Wednesday: Mostly cloudy, light flurries 2-4cm, treeline temperatures around -2C, light SW windsThursday: Snowfall 15-25cm, freezing levels rising to 1000-1500m, light to moderate SW winds

Avalanche Summary

No natural activity has been reported since Saturday. On Sunday several explosive and human triggered avalanches were reported up to size 3. This includes a skier remote size 2.5 on a crust/facet interface down 150 cm on a SW aspect at 2300m and a skier triggered size 1.5 wind slab on a NE aspect at 1800m.

Snowpack Summary

Roughly 30 cm of new snow has fallen since Saturday. Winds have been generally moderate to strong from the SW-NW and temperatures have fluctuated. Expect to find touchy wind slabs in exposed lee terrain at and above treeline, and buried rain crusts below 1600 m. A couple buried weak layers (surface hoar or facets) are now down 80-100 cm deep. Snowpack depths vary, but in general 150 cm of snow can be found at treeline, with 100-200 cm in the alpine. In many places we're still dealing with a relatively thin snowpack (thanks to a windy early season) so there's not a whole lot of snow between riders and the sugary snow (facets) near the ground. The basal facet/crust combo has been recently active in parts of the region and continues to give easy to moderate results in snowpack tests.

Problems

Storm Slabs

Storm slabs and wind slabs continue to build and may release naturally with more load or from the weight of a rider. Watch for touchy wind slabs on exposed north through southeast facing slopes and cross-loaded features well into treeline.

Stick to simple terrain and be aware of what is above you at all times.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

Several persistent weaknesses exist in the upper and mid-snowpack and could be triggered by the weight of a skier or rider or from continued loading from snow and wind.

Whumpfing is direct evidence of a buried instability, if observed back off to lower angle terrain. >Use conservative route selection, stick to moderate angled terrain with low consequence.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Deep Persistent Slabs

A weakness near the base of the snowpack could be triggered by continued loading or by riders in thin snowpack areas.

Avoid rock outcroppings, steep convexities and anywhere the snowpack feels thinner than average.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Dec 31st, 2013 2:00PM