Avalanche Forecast

Issued: Jan 21st, 2014 8:24AM

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

bcorrigan, Avalanche Canada

Kootenay Boundary.

Summary

Confidence

Good - Due to the quality of field observations

Weather Forecast

No precipitation in sight for the next few days. The ridge of high pressure continues to dominate the weather pattern blocking Pacific moisture from the BC and western Alberta.Tonight:Â Nil precipitation, wind light at ridge tops, freezing level at 500m.Wednesday: Nil precip.,light ridge tp winds, freezing level to 1400m.Thursday: NIlÂ precipitation, winds light at ridge tops, freezing level to 1400m.Friday:Â NIlÂ precipitation, winds light at ridge tops, freezing level to 1700m.

Avalanche Summary

No reports of recent avalanche activity in the forecast region, although sluffing continues in steep terrain, snowballing and pinwheel activity on steep solar aspects during the warmest parts of the day.

Snowpack Summary

Wind continues to redistribute surface snow throughout the region, and basal facets continue to be a concern where wind slabs and storm slabs have added load above these weak layers. The forecast very warm alpine temperatures may result in periods of rapid warming in the wind and storm slabs above weak layers. Strong solar radiation may cause moist or wet loose snow avalanches or cornice falls in the alpine resulting in large additional loads above deeply buried weak layers. Surface hoar continues to form on protected north and east slopes along with facetting of the surface and storm slab in protected locations. Solar aspects haveÂ sun crust in some locations.

Problems

Deep Persistent Slabs

This problem is more likely in areas that had a shallow snowpack during the cold arctic outbreak. Loose wet avalanches or cornice falls may trigger deeply buried weak layers resulting in large destructive avalanches.

Avoid lingering in runout zones.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Wind Slabs

Wind slabs continue to grow on lee slopes at tree line and above. In some areas these slabs may be up to one metre thick. Warm temperatures may result in loose wet avalanches on southerly aspects, or cornice falls, triggering these wind slabs.

Avoid convexities or areas with a thin or variable snowpack.>Avoid shallow snowpack areas where triggering is more likely.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

Storm snow may not have bond well to the surface hoar and melt-freeze crusts that developed before the storm. Forecast warm temperatures may result in easier triggering of these slabs

Be aware of thin areas that may propogate to deeper instabilites.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Avoid slopes with glide cracks.>Assess start zones carefully and use safe travel techniques.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Jan 22nd, 2014 2:00PM