Avalanche Forecast

Issued: Dec 11th, 2012 8:52AM

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

slemieux, Avalanche Canada

Cariboos.

Summary

Confidence

Fair

Weather Forecast

A weak ridge moving over the region should bring lighter precipitations for Wednesday and then partial clearing. The next system is weaker and should reach the region Thursday and deliver some light precipitations and stronger Southwesterly winds for the rest of the period. Cool temperatures (-12 C) and lighter winds are expected for Friday.

Avalanche Summary

No new avalanches were reported for this region. However, I suspect that there has been some recent natural activity with the new load and winds on lee slopes.Â

Snowpack Summary

30-40 cm of fresh snow in the past couple days and the moderate to strong winds from the Northwest and Southwest has created the windslab problem on lee slopes in the alpine and treeline. This new snow could also be burying older and deeper windslabs in the alpine. Sluffing is still an issue on steep features protected from the wind below treeline. Below treeline, also watch for early season obstacles, such as stumps and creeks.Â The deep persistent instabilities (surface hoar and early November crust) located in the middle and near the bottom of the snowpack are still a concern in this region, however, we haven't had report of their sensitivity or reactiveness. Digging down and making your own observations will be critical to safe slope selection. Any observations from the field are welcome at forecaster@avalanche.ca.

Problems

Wind Slabs

Expect buried windslabs in sheltered area and newly formed windslabs in exposed lee slopes and cross-loaded gullies below ridge crests.

Be aware of the potential for wide propagations due to the presence of hard windslabs.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Deep Persistent Slabs

Be extra careful in areas where ground roughness is not present to act as anchorage. Smooth ground cover areas include firn on glaciers, grassy slopes and rock slabs.

Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 7

Valid until: Dec 12th, 2012 2:00PM