Avalanche Forecast

Issued: Jan 12th, 2013 8:47AM

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

Avalanche Canada pmarshall, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Sunday: Mainly cloudy with sunny breaks and a chance of flurries. Temperatures should remain cool during the day but an above freezing layer (AFL) is expected to develop late in the day. Winds are moderate to strong from the northwest.Monday: Mainly sunny. The AFL strengthens with alpine temperatures expected to reach +5. Winds remain strong from the northwest.  Tuesday: Mainly cloudy with a chance of precipitation. The AFL should dissipate but the freezing level remains relatively high at 1600-1800 m. Winds remain strong from the northwest.  

Avalanche Summary

There are no new natural avalanche reports. Explosive control work near highway corridors over the past couple days produced several avalanches up to size 3.5. Some of these slides released on the late December surface hoar or facet layer and propagated widely.

Snowpack Summary

Northerly outflow winds have produced new wind slabs in exposed lee and cross-loaded terrain. 60-90 cm of storm snow from last week continues to settle and gain strength. However, a weak layer of surface hoar or facetted snow sits at the base of the storm snow. Recent snowpack tests give generally moderate sudden planar, or "pops", results on this buried surface hoar layer and indicate potential for wide propagation. Near the base of the snowpack, a crust/facet layer continues to concern local avalanche professionals. This weakness is unlikely to be triggered by a single person, but it remains possible with a very heavy load (e.g. cornice fall) or from a thin-spot trigger point.

Problems

Persistent Slabs

An icon showing Persistent Slabs
A weak layer of surface hoar and/or facetted snow exists under the recent storm snow and has been susceptible to human triggering.
Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

An icon showing Wind Slabs
Northerly outflow winds have created new wind slabs in exposed lee and cross-loaded terrain.
Avoid freshly wind loaded features.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 13th, 2013 2:00PM

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