Avalanche Forecast

Issued: Feb 20th, 2013 8:28AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Cornices.

Avalanche Canada pmarshall, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Synopsis: A series of frontal systems is expected to affect the region over the next few days bringing steady precipitation and seasonal temperatures.  Overnight and Thursday: Periods of snow – 20-30 cm. The freezing level is around 600 m. Winds are moderate to strong from the west-southwest. Friday: Heavy snowfall – 30-40 cm. The freezing level remains around 500-600 m and winds are strong from the west.Saturday: Cloudy with light snow. The freezing level is around 500 m and winds ease to moderate from the southwest.

Avalanche Summary

Recent natural avalanche activity is limited to size 1-1.5 loose snow avalanches in steep terrain. Explosive control in Bear Pass produced a few size 2-2.5 slab avalanches on Tuesday.

Snowpack Summary

A layer of surface hoar and a sun crust are now buried by a few cm's of new snow. Below this the recent storm snow has settled and gained strength over the past couple days. Pockets of wind slab have formed on a variety of aspects in exposed terrain near ridge crests, and may be susceptible to triggering in steep terrain. Cornices that now loom over many features may become weak with continued growth and/or daytime warming. The mid and lower snowpack layers are generally well settled.

Problems

Storm Slabs

An icon showing Storm Slabs
New snow may not bond well to the previous snow surface (surface hoar, wind slab, sun crust) and may be easily triggered by the weight of a rider. Be especially wary of exposed north through east facing slopes where wind loading is likely.
Avoid freshly wind loaded features.>Whumpfing, shooting cracks and recent avalanches are all strong indicators of an unstable snowpack.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 5

Cornices

An icon showing Cornices
The recent snow and wind have been building cornices on lee features. These cornices are likely weak and may fail at anytime. Cornice failure has the potential to trigger large avalanches.
Give cornices a wide berth when travelling on or below ridges.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Feb 21st, 2013 2:00PM