Avalanche Forecast

Issued: Jan 20th, 2013 9:48AM

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

slemieux, Avalanche Canada

Cariboos.

Extent of solar radiation and warming influence is uncertain. Use extra caution as the day progresses especially on South facing slopes.

Summary

Confidence

Fair

Weather Forecast

Sunday night and Monday: The ridge of high pressure continues to bring dry conditions, well above normal temperatures.Â Inversion with temperatures reaching close to 0 degrees in the alpine, few clouds cover with valley clouds and moderate NW winds. Freezing level rising during the day to 1100 m.Tuesday: The ridge is moving slowly Eastward bringing more mild temperatures, few clouds and valley clouds and lighter winds from the NW. Similar temperatures, with freezing level remaining around 1000 m. Wednesday: A weak system should reach the region later during the day bringing light precipitation (12 mm), cooler temperatures (-8 C) and Southerly winds.Â

Avalanche Summary

No new avalanche was reported.

Snowpack Summary

The warm temperatures and solar radiation forecasted for tomorrow could weaken the recent windslabs and persistent slabs, especially those found on steep South facing slopes. If surface snow becomes moist, loose wet avalanches could also take place, and even though small in size, they could become a problem if thrown off your feet in a terrain trap. The recent storm snow sits above surface hoar layer, a sun crust on steep S to SW -facing slopes and facets. The surface hoar layer is still producing easy to moderate sudden planar shears below 1500 m. in sheltered areas. The distribution of these weaknesses is patchy, but where they exist, they may be triggered by the warming trend or under with the weight of a person or snowmobile. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.

Problems

Wind Slabs

Solar radiation and warm temperatures could weaken some steep wind loaded slopes. Triggering a windslab could potentially step down to a deeper instability.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Persistent Slabs

A very cautious approach is recommended on steep south-facing slopes and sheltered terrain below treeline with daytime warming and solar radiation possibly weakening the snowpack.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Jan 21st, 2013 2:00PM