Avalanche Forecast

Issued: Jan 29th, 2012 9:49AM

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

Avalanche Canada jlammers, Avalanche Canada

If you're heading into the Bonnington Range, please see our Forecast Details page for specific snowpack information.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Monday: continued moderate snowfall / moderate west winds with strong gusts / freezing level at 900mTuesday: trace amounts of snow / light to moderate southwest winds / freezing level between 900 and 1000mWednesday: light snow in the morning with a clearing trend developing in the afternoon / light westerly winds and rising freezing levels

Avalanche Summary

Numerous fresh windslab avalanches to size 1.5 were observed in the region over the last 24 hours. More deep activity was reported from the Bonnington Range on Saturday where a size 2.5 and a size 3 avalanche were reported to have released on the mid-December surface hoar/facet layer.

Snowpack Summary

Warmer temperatures, moderate southwest winds and moderate snowfall throughout the weekend continued to add to an ongoing wind slab issue creating cohesive and reactive wind slabs at treeline and in the alpine. In some parts of the region underlying storm snow from mid-week is sitting on a freezing rain crust that developed on Tuesday morning. Reactivity on the crust (which sits about 35cm below the surface in most wind-neutral areas) may develop with increased load. A few operators are also talking about a surface hoar layer that was buried on January 14th. Its reactivity has been described as "stubborn", but it has potential to size 3. A layer of concern deeper in the snowpack is the surface hoar/facet layer from mid-December. This layer has become less of a concern in the vast majority of locations. In the Bonnington Range, however, it is still on the radar of backcountry travelers as the layer is still reactive and is producing avalanches to size 3 in isolated features. This lingering layer of concern reflects the variability of the snowpack within the region. Snowpack depths in the region are around 230 cm at treeline.

Problems

Wind Slabs

An icon showing Wind Slabs
Moderate temperatures, continued snowfall and moderate to strong southwest winds winds have set up cohesive new wind slabs in the lee of exposed features at treeline and in the alpine

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
Forecast snow will add to the current storm slab problem. Watch for storm slabs on steeper, unsupported features

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 30th, 2012 8:00AM