Avalanche Forecast

Issued: Nov 25th, 2014 8:41AM

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

Avalanche Canada jlammers, Avalanche Canada

The avalanche danger is expected to increase as weather systems roll across the province and add to the developing storm slab. Buried weak layers have the potential to surprise with nasty consequences.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

A low pressure system off the coast will move inland bringing significant precipitation across the south of the province on Wednesday and Thursday. Uncertainty lies in precipitation amounts and freezing levels; however, some models indicate heavy precipitation and freezing levels reaching 2000m. On Friday a northwest flow will bring cooling, light flurries and a mix of sun and cloud.Wednesday: 15-25cm of snow / Moderate west winds / Freezing levels rising from 1000 to 2000m throughout the dayThursday: 15-20cm of snow / Strong southwest winds / Freezing levels at about 2000mFriday: Mix of sun and cloud with light flurries / Light northwest wind / Freezing level at surface

Avalanche Summary

Observations have been extremely limited, although numerous size 1 storms slabs were observed in recent days in the Kootenay Pass area. Avalanche activity will likely increase in size and frequency with forecast wind, snow and rising freezing levels.

Snowpack Summary

As we begin our forecasting season we are working with very limited field data. If you have been out in the mountains, please send us a note with your observations to forecaster@avalanche.ca.Up to 70cm of storm snow has fallen over the past week, and continual storms are contributing to ongoing surface instabilities within the new snow. The developing storm slab is adding load to weak crystals at the base of the snowpack which formed during the recent dry spell. These weak crystals, which include facets, surface hoar and possibly crusts, become more reactive at higher elevations and may persist for some time with the potential for large and destructive avalanches.The limited field data that we have received suggests that there is not enough snow below treeline for avalanche activity.If you are sending us information, we are interested in snow depths at different elevations (alpine, treeline, below treeline), spatial extent of the crust/facet weak layer, and new snow/ storm snow amounts.

Problems

Storm Slabs

An icon showing Storm Slabs
The avalanche danger is expected to increase as warm and punchy weather systems roll across the province. The developing storm slab may be extra touchy in wind-exposed terrain, or at upper elevations where buried weak layers are likely to exist.
Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>Good day to make conservative terrain choices.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Valid until: Nov 26th, 2014 2:00PM

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