Avalanche Forecast

Issued: Feb 13th, 2014 8:32AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

Friday: Continued moderate snowfall / Strong southwest winds / Freezing level at 500mSaturday: Light snowfall becoming moderate to heavy overnight / Strong southwest winds / Freezing level at 800mSunday: Light snowfall / Strong southwest winds / Freezing level at surface

Avalanche Summary

Numerous size 2 natural storm slab avalanches were observed on Wednesday. As well, a few size 2.5 storm slab avalanches were remotely triggered from up to 200m away. This speaks to the highly touchy nature of the current instability. Due to the nature of the buried weak interface and forecast weather, ongoing destructive storm slab activity will continue.

Snowpack Summary

In many areas over 60cm of recent snowfall overlies a medley of old surfaces which include: weak surface facets, surface hoar, a scoured crust, or any combination thereof. Reports from the field indicate a very poor bond between the new snow and these old surfaces with accounts of whumphing and easy, sudden planar snowpack tests. Strong winds and slight warming have added cohesion to the new storm slab, and have shifted the new snow into deeper, destructive wind slabs in exposed terrain. The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but triggering has become unlikely.

Problems

Storm Slabs

An icon showing Storm Slabs
A very touchy and destructive storm slab sits over weak surfaces which formed during the long cold snap. More snow in the forecast will add to the size and reactivity of the avalanche problem. Conservative terrain selection is now critical.
Use conservative route selection, stick to moderate angled terrain with low consequence.>The very touchy conditions require extreme caution if travelling in the mountains.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Valid until: Feb 14th, 2014 2:00PM