Avalanche Forecast

Issued: Feb 21st, 2013 10:19AM

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

Avalanche Canada jfloyer, Avalanche Canada

New snow and strong winds are expected to set up dangerous avalanche conditions on Friday and for the weekend.

Summary

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain on Friday

Weather Forecast

Synopsis: An intense storm will impact the region on Friday afternoon/evening, then briefly clearing on Saturday before another storm hits later on Sunday.Friday: 15-20 cm new snow is expected. Strong southwesterly winds to 60 km/h at ridgetop. Freezing level 1000 m.Saturday: Light snow in the morning, clearing in the afternoon. Winds becoming light northwesterly. Freezing level 800 m.Sunday: Light snow starting late in the day. Light southwesterly winds. Freezing level around 800 m.

Avalanche Summary

A few small, soft slab avalanches were reported on Thursday. Several loose snow avalanches have been also been reported in steep terrain.

Snowpack Summary

10-25 cm of recent snow overlies a pair of surface hoar layers buried mid February (Feb 12th and Feb 16th). The burial depth of these layers is still shallow, and for the most part the snow above is still light. However, there may be isolated slopes where the wind has blown the new snow into wind-stiffened deposits sufficiently deep to create a potentially harmful slide. Additionally, the well-developed crystals associated with these interfaces indicate they may stay with us for a while and present bigger problems as they become more deeply buried. Two previous buried surface hoar/facet/sun crust layers approximately 30 and 50 cm below the surface (Feb 4th and Jan 23, respectively) are still being tracked by professionals but have not been reactive recently. These layers may be worth investigating on a safe, representative adjacent slope if you are considering riding in aggressive terrain.

Problems

Storm Slabs

An icon showing Storm Slabs
Loading from new snow and wind will rapidly increase avalanche danger, particularly in exposed lee areas, where significant wind slab deposits are expected to develop.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Choose well supported terrain without convexities.>Stick to simple terrain and be aware of what is above you at all times.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

2 - 5

Valid until: Feb 22nd, 2013 2:00PM