Avalanche Forecast

Issued: Mar 6th, 2014 9:24AM

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

jlammers, Avalanche Canada

Cariboos.

This weekend's weather forecast includes higher freezing levels and rain to mid-mountain elevations. This will have a destabilizing effect on the snowpack with avalanches increasing in size and frequency.

Summary

Confidence

Fair - Freezing levels are uncertain on Friday

Weather Forecast

Friday: Light snowfall / Moderate to strong southwest winds / Freezing level at surface climbing to about 1800m in the eveningSaturday: Up to about 30cm of snow at higher elevations / Moderate to strong southwest winds / Freezing level at about 1800mSunday: Up to about 30cm of snow / at higher elevations / Moderate to strong southwest winds / Freezing level up to about 1800m

Avalanche Summary

In recent days natural wind slab avalanches to size 1.5 were reported in response to new snow and wind.

Snowpack Summary

In general, about 20-40cm of storm snow overlies small surface hoar crystals in sheltered areas, a sun crust on solar aspects and wind slabs in exposed terrain. The recent snowfall exists as pockets of wind slab in exposed terrain. Further snowfall, wind and warming will add to the reactivity and destructive potential of this developing storm slab. There is ongoing concern for a mix of weak surfaces which were buried on February 10th. This persistent interface lies up to a metre below the surface, and includes weak surface hoar, well developed facets and a mix of hard surfaces which remain widespread at all aspects and elevations. Although natural avalanche activity has tapered-off at this interface, destructive avalanches are still a concern with recent reports of rider-triggering in alpine terrain. For the most part, the mid and lower snowpack are strong and well consolidated. Weak basal facets exist in some areas, but triggering has now become unlikely.

Problems

Persistent Slabs

A deep, dense slab overlies a variety of weak layers and may still be reactive in some areas. Triggering this weakness would have nasty consequences, so be patient and don't be tempted into large, unsupported terrain.

Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Storm Slabs

Up to 40cm of recent storm snow overlies a number of potentially weak surfaces. Watch for increased reactivity in wind exposed terrain.

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

Valid until: Mar 7th, 2014 2:00PM