Avalanche Forecast

Issued: Feb 7th, 2012 8:50AM

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

Avalanche Canada pgoddard, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Wednesday: Cloudy with light precipitation starting in the afternoon. Southerly winds increasing by afternoon. Freezing level around 800m.Thursday/Friday: A series of fronts is forecast to bring light snow to the area (perhaps 15-25mm total, with highest amounts in the north). The timing and amount of precipitation are still uncertain, but the general picture is for precipitation to decrease during Thursday morning and increase again by Thursday evening, with moderate to strong southerly winds. The freezing level should rise to around 1500m by Friday.

Avalanche Summary

Wind loading led to a localized avalanche cycle near Stewart on Sunday and skiers triggered small pockets of slab on convex rolls at treeline on Monday. Several solar-triggered avalanches have been observed on sunny slopes during the heat of the day and warm temperatures led to avalanches, even on shady north aspects, below about 1100m on Monday. A couple of avalanches pulled out the Jan 20 facet layer on Monday with heavy triggers.

Snowpack Summary

Strong outflow winds from the east have created new wind slabs. Recently, temperatures have been unseasonably warm, leading to moist or wet weak surface snow conditions. Where a re-freeze has occurred, a crust now exists. Recent storm snow appears to be well settled. A facet layer buried on Jan 20th still exhibits hard, sudden planar results in isolated snowpack tests and avalanches are occasionally failing on this layer with large triggers. It's about 120-150cm deep in the snowpack. Cornices will be weakest during the heat of the day and have the potential to act as a trigger for deep avalanches on the slope below.

Problems

Cornices

An icon showing Cornices
Large cornices are looming over some slopes and could act as a trigger for large, deep avalanches if they collapse.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

3 - 7

Wind Slabs

An icon showing Wind Slabs
Recent outflow winds have created wind slabs behind ridges and terrain breaks. Winds are forecast to change direction and increase in strength, potentially leaving wind slabs on slopes facing all directions. Take extra care on steep or convex terrain

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 8th, 2012 3:00AM