Avalanche Forecast

Issued: Dec 5th, 2013 7:38AM

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

ccampbell, Avalanche Canada

Northwest Inland.

This forecast is based on limited field observations. If you head into the mountains, please send a note to forecaster@avalanche.ca and let us know what you saw.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: An arctic ridge of high pressure will persist over the BC Interior and Yukon for the next several days. Friday: Mainly sunny with extreme outflow winds in the valleys and moderate to strong northeasterly alpine winds. Treeline temperatures expected to be around -10. Saturday: Mainly sunny with some thin cloud possible, outflow winds easing moderate in valley bottoms and light to moderate northeasterly alpine winds. Treeline temperatures expected to be around -15 but not much colder in the alpine. Sunday: Increased cloud, windy, and cold with the possibility of above freezing temperatures between 1500m and 2000m.

Avalanche Summary

Several wind slab avalanches up to Size 2 were observed just below ridge crests between 1500m and 1800m in the Ashman Ridge area last Sunday.

Snowpack Summary

Recent storm snow is settling and gaining strength, however weaknesses at the old snow interface down approximately 40cm may still need time to heal. In the Ashman Ridge area on Sunday, this interface gave easy compression test results. Northerly outflow winds are likely forming fresh wind slabs in exposed lee terrain and scouring windward terrain. Average snowpack depths near treeline are highly variable, but around a metre in sheltered areas.

Problems

Wind Slabs

Outflow winds are reverse-loading and cross-loading exposed slopes. Fresh and touchy wind slabs are likely lurking below ridge crests and behind terrain features.

Avoid freshly wind loaded features.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be cautious as you transition into wind affected terrain.>Avoid travelling in areas that have been reverse loaded by winds.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 6th, 2013 2:00PM