Avalanche Forecast

Issued: Dec 2nd, 2014 7:39AM

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

ghelgeson, Avalanche Canada

Kootenay Boundary.

Riding north of Nelson? Take a look at the South Columbia forecast. Please email your observations to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Synopsis: Fairly static weather pattern for another few days. It looks like the dry and cold northwest flow will be replaced by moist and warm southwest flow on Saturday. Wednesday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, Variable | Ridgetop: Light, SW Thursday: Freezing Level: Valley Bottom; Precipitation: 0-2mm | 0-4cm; Wind: Treeline: Light, Variable | Ridgetop: Light, SWFriday: Freezing Level: 500m; Precipitation: 0-6mm | 0-8cm; Wind: Treeline: Light, SW | Ridgetop: Moderate, SW

Avalanche Summary

No new avalanche activity to report.

Snowpack Summary

This forecast is based off a very small data set. Here's the best information I can offer:The snowpack north of Nelson is a different beast than the rest of the forecast region. If you're recreating north of Nelson, the South Columbia forecast does a better job of describing the more complex snowpack and the associated Persistent Slab Problem. In the north it appears that two buried weak layers may be problematic: The mid November surface hoar/facet/crust combo down 70 - 90 cm and the weak sugary snow (large facets) near the ground.In the southern portion of the region reports indicate that a weakness is not present near the ground. The Black Friday rain to cold snow storm left 10 - 25 cm of snow on top of a supportive 20 cm thick crust.

Problems

Storm Slabs

These are likely getting harder to trigger, but watch for isolated wind slabs in exposed terrain, especially above treeline.

Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Portions of the region north of nelson may be capable of producing large avalanches due to two problematic layers in the snowpack. Reports are limited. Dig down and investigate for yourself before committing to bigger terrain.

Avoid shallow snowpack areas where triggering is more likely.>Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Dec 3rd, 2014 2:00PM