Avalanche Forecast

Issued: Jan 18th, 2012 9:24AM

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

Avalanche Canada pgoddard, Avalanche Canada

Summary

Confidence

Good - -1

Weather Forecast

Thursday: One more day of frigid cold to endure - although some minor warming may creep into the far south. Light winds. No precipitation.Friday: Light snow starting late in the day. Moderate south-westerly winds and temperatures rising slightly. Saturday: Continued light to moderate snowfall. South-westerly winds.

Avalanche Summary

Skiers triggered wind slabs to size 2 on mostly easterly aspects on Tuesday. A couple of natural wind slabs up to size 2.5 were also reported. In terrain not so affected by the wind, natural and skier-triggered soft slabs and sluffs were observed on steep slopes and convex rolls.

Snowpack Summary

Recent storm snow totals are about 40-60cm. This sits over a variety of surfaces (facets, surface hoar in sheltered areas, soft slabs, hard slabs, wind crust, and a melt-freeze crust below treeline) The dry storm snow only been reacting as a slab in a few areas, with loose and fast sluffs the main concern in others. Localised strong winds on Tuesday night have led to wind slabs at treeline and above, mainly on easterly aspects.A surface hoar layer buried in mid-December is gaining strength, but professionals are still treating it with caution, as the consequences of an avalanche on this layer would be high. It's now down about 120cm in the snowpack and could potentially be triggered from a shallow snowpack area or by a very heavy load, like cornice fall or group of sledders).

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are easy to trigger behind ridges and terrain breaks and in cross-loaded gullies. Strong winds at low elevations have built wind slabs in openings below treeline as well.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
Up to 50cm of storm snow is settling slowly into a soft slab in places sheltered from the brunt of the wind. In other sheltered, steep terrain, loose dry sluffing is still a concern. Sluffs can entrain mass and become quite large.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 19th, 2012 8:00AM