Avalanche Forecast

Archived

Jan 22nd, 2013–Jan 23rd, 2013

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

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.

Regions

Little Yoho.

Weather Forecast

Wednesday night a cold front will move across the area bringing cooler temperatures and scattered flurries through to Friday.

Snowpack Summary

Recent strong winds have created widespread wind effect in the alpine. Windward slopes are scoured and hard and soft slabs that are reactive to skier triggering exist elsewhere. In shallow snowpack areas the mid-pack has facetted out and become weaker. Below 2200 m surface hoar exists in some locations and produces moderate results with Comp. Test.

Avalanche Summary

Natural avalanche activity has stopped however wind-slabs in the alpine are proving to be reactive to skier triggering in some areas. A Class 2 wind slab on north aspect at 2400 m near Bow Summit was triggered by skiers on Monday. A class 1.5 wind slab (north aspect, 2300m) was triggered on Observation peak in past three days.

Confidence

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.