Avalanche Forecast

Issued: Feb 28th, 2012 9:28AM

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

pgoddard, Avalanche Canada

Cariboos.

Check out the Forecaster's Blog below for some thoughts on managing the current tricky conditions.

Summary

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Wednesday: Cloud and flurries. Freezing level 600m. Light to moderate southerly winds.Thursday: Sun, cloud and flurries. Light to moderate north-westerlies. Freezing level valley bottom.Friday: Cloudy, with about 5cm snow. Strong westerlies. Freezing level valley bottom.

Avalanche Summary

An avalanche cycle which began on Wednesday has slowed slightly with time, but conditions remain touchy with natural, human and remotely-triggered avalanches in the size 1.5-3 range reported most days. These are running on storm snow weaknesses or on buried weak layers in the upper snowpack. As snowfall and wind-loading ease over the next few days, expect natural avalanches to decrease, but tricky and touchy conditions for human-triggering to continue.

Snowpack Summary

60-140cm recent storm snow is settling above the Feb 16. surface hoar layer and the early Feb. interface. The early Feb. interface consists of surface hoar (observed into the alpine, but most commonly found at and below treeline) and/or a crust (found on solar aspects, and on all aspects below about 1600m). These weaknesses are still very touchy in certain locations and can be triggered remotely or by light loads. Old and new wind slabs, which exist on a variety of slopes, could step down to a persistent weakness and create a surprisingly large avalanche. Large cornices loom in some areas. Shallow snowpack areas may still harbour basal facets.

Problems

Persistent Slabs

Several weaknesses exist in the upper metre or so of the snowpack. These layers are tricky to manage, as they are very touchy in some locations and not in others. Large, destructive avalanches could be triggered by a light load, even from a distance.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 6

Wind Slabs

Wind slabs are lurking on a variety of slopes. Persistent weak layers are buried beneath these slabs, meaning they could step down and create very large avalanches. Large cornices also threaten many slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 6

Valid until: Feb 29th, 2012 8:00AM