Avalanche Forecast

Issued: Nov 28th, 2012 10:31AM

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

jlammers, Avalanche Canada

Kootenay Boundary.

This bulletin is based on a very limited data, and significant variations in conditions exist.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Light snowfall is expected to start Wednesday evening and intensify throughout the rest of the forecast period.Ridgetop winds are forecast to be moderate to strong from the southwest on Thursday trending to strong and southwesterly on Friday and Saturday.Freezing levels should stay at about 1450m for the entire period.

Avalanche Summary

No new avalanches have been reported. If you and your friends have been out exploring and riding in the backcountry, and have some observations to share please send an email to forecaster@avalanche.ca.

Snowpack Summary

Healthy amounts of snow fell throughout the last week; however, the more recent break in the weather has given the upper snowpack a chance to settle and gain strength. Over the last few days, surface hoar may have formed and will be something to watch as the next system moves in to the region on Thursday.In the mid snowpack there may be a spotty, thin buried surface hoar layer between 50 and 80cm down. At the base of the snowpack sits the early November rain crust. Located about 100cm below the surface, it seems most likely to be found in deeper snowpack areas and may have associated facets. These layers seem to have been unreactive in recent days, but may have the potential to 'wake-up' with forecast loading.

Problems

Storm Slabs

Forecast weather will create reactive storm/ windslabs. Watch for triggering below ridgecrests, in gullies and behind terrain features

Use extra caution during periods of heavy loading from new snow and wind.>

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 4

Persistent Slabs

Although reactivity has been limited, persistent layers represent a low probability-high consequence scenario. Persistent slabs may "wake-up" with additional loading.

Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Nov 29th, 2012 2:00PM