Avalanche Forecast

Archived

Dec 2nd, 2013–Dec 3rd, 2013

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland.

Data is very limited from the region. Please send your field observations to [email protected].

Confidence

Poor - Due to the number of field observations

Weather Forecast

Tonight and Tuesday: Clear and cold. Expect mountaintop temperatures to dip close to -20. Strong outflow winds from the North-Northeast are forecast.Outlook: Continued cold and clear weather should be the story all week. Alpine temperatures should hover between -15 and -25, and winds should remain moderate to strong from the Northwest-Northeast.

Avalanche Summary

Several wind slab avalanches up to size 2 were observed in the Ashman Ridge area on December 1. These were from wind loaded areas just below ridge crests between 1500 and 1800 m.

Snowpack Summary

Observations from the region are very limited. One recent report from the Ashman Ridge area southwest of Smithers indicates that snowpack depths range from 80-160 cm near treeline. There is around 40 cm of new storm snow that is bonding poorly to the underlying surface. Recent southerly winds have formed touchy wind slabs in exposed lee terrain at treeline and above. Previous warm temperatures and rain saturated the snowpack below 1200 m and created a rain crust. The average snowpack depth in the region is around 60-90 cm at 1200-1400 m elevation.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.