Avalanche Forecast

Issued: Jan 30th, 2013 9:27AM

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

triley, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Saturday

Weather Forecast

Overnight and Thursday: The Northwest flow is expected to continue to push the cold arctic air to the East. Northwest winds moderate overnight becoming light Westerly. No precipitation is expected tonight, and light snow falls of 5-8 cms are expected on Thursday. Alpine temperatures gradually warming on Thursday and freezing levels rising to about 1300 metres.Friday: No precipitation is expected as a high pressure system in the South influences most of the interior mountain ranges. Expect high cloud or broken skies. Freezing level at about 800 metres.Saturday: High pressure should continue to influence. No precipitation expected, and freezing level at about 1000 metres.

Avalanche Summary

One natural slab avalanche size 1.5 was reported that was about 30 cms deep.

Snowpack Summary

Some areas in the Northern parts of the region received another 20-25 cms of dry light snow. The variable surfaces that were left behind by the end of the snow drought on January 23rd are now buried by 50-80 cms of incremental storm snow. In some areas the storm snow has settled into a 30 cm layer that may be reactive where it sits above a weak layer of old surface hoar or facets that grew during the drought. There is a lot of loose snow available for transport if the winds develop into strong values.

Problems

Wind Slabs

There is a lot of loose dry snow available for transport as the Northwest winds build. Watch for soft wind slabs developing in the lee of terrain features.

Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

Two surface hoar layers lie buried under the surface, one approximately 40cm down and the other approximately 80cm down. Both are reported to be patchy and variable in distribution. Most likely triggered on steep convex rolls at treeline or below.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>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

1 - 4

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