Avalanche Forecast

Issued: Dec 19th, 2013 7:41AM

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

Avalanche Canada Peter, Avalanche Canada

Summary

Confidence

Fair

Weather Forecast

Friday: Cloudy with light to moderate snowfall – around 5 cm. The freezing level is at valley bottom and ridgetop winds are moderate but gusty from the west-northwest. Saturday: Mainly cloudy with a chance of flurries and sunny breaks. The freezing level could jump to 700 m and moderate gusty northwest winds continue. Sunday: Possible sunny breaks and flurries. The freezing level could climb to 1200 m and the upper flow continues to be northwesterly.

Avalanche Summary

No avalanches have been reported in the last few days.

Snowpack Summary

It's been an exceptionally dry December so far. The total monthly precipitation in Nelson is 40 mm, and 30 mm of that fell in one storm at the beginning of the month. Hopefully the weather pattern changes soon!Recent light snowfall and strong westerly winds formed pockets of soft wind slab on lee slopes and scoured windward slopes in exposed terrain. Between 35 and 50cm below the surface you may find a weak layer of surface hoar on sheltered slopes or a melt-freeze crust on steep solar aspects. Most reports indicate this layer is "stubborn" to trigger, or there may not be a deep enough overlying slab to create a significant hazard. That said, I'd remain curious about this interface, especially as the snow load above gradually increases.In general, snowpack depths are below seasonal average and many slopes below treeline are reported to be below threshold for avalanche activity. Deeper snow is likely in the northern part of the region.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent strong westerly winds have produced pockets of dense wind slab in exposed lee terrain and cross-loaded features. Rider triggering is possible, particularly in steep unsupported terrain.
Use ridges or ribs to avoid pockets of wind loaded snow.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 20th, 2013 2:00PM