Avalanche Forecast

Issued: Feb 13th, 2014 8:27AM

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 - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

Friday: Moderate to locally heavy 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

A widespread avalanche cycle to size 2.5 was observed on Wednesday. The storm slabs failed on a variety of aspects and elevations. In at least one case, an avalanche was triggered remotely from a distance of 30m. This speaks to the highly touchy nature of the current instability.

Snowpack Summary

Between 60 and 100cm of recent snowfall overlies a medley of old surfaces which were buried on February 10th. These layers include: weak surface facets, surface hoar, a scoured crust, or any combination thereof. Professionals are expressing particular concern for the combination of buried facets on a crust being unusually reactive at treeline and below. Reports of whumphing and widespread avalanche activity further indicate a poor bond between the new snow and these old surfaces. Strong to extreme winds are shifting the new snow into deeper, reactive wind slabs in exposed terrain. With forecast warming and more snow on the way, the reactivity and destructive potential of the new storm slab will likely increase.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 touchy and destructive storm slab, which has shown reactivity at all elevation bands, sits over a variety of potentially weak surfaces which formed during the recent cold snap. Conservative terrain selection has become critical.
The touchy conditions will require extreme caution if traveling in the mountains.>Use conservative route selection, stick to moderate angled terrain with low consequence.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

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