Avalanche Forecast

Issued: Mar 3rd, 2014 8:19AM

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

jlammers, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Track of incoming weather systems is uncertain

Weather Forecast

Overview: A series of disturbances are embedded in a west/southwesterly flow which will bring continued snowfall to the region. There is some model disagreement in the track of the systems; however, southern areas of the interior are expected to see the highest accumulations.Tuesday: Light snowfall / Moderate westerly winds / Freezing level at surfaceWednesday: Light to locally moderate snowfall / Light ridgetop winds / Freezing level at surfaceThursday: Light snowfall / Light ridgetop winds / Freezing level at surface

Avalanche Summary

Numerous size 2-2.5 sled-triggered slab avalanches occurred in the Valemount area over the last week. The February 10th interface was the culprit in these events. Isolated reports of remotely triggered avalanches in neighbouring regions also suggest that large slab avalanches on the February 10th interface are still a real possibility. A couple of size 2 wind slab avalanches were also noted on northwest facing terrain on Sunday. They formed in response to redistribution of surface snow due to strong winds over the weekend.

Snowpack Summary

Light to locally moderate amounts of new snow overlie small surface hoar crystals in sheltered areas, a sun crust on solar aspects and recently formed wind slabs in exposed terrain. Initially, these new accumulations are expected to be reactive as wind slab in pockets of exposed terrain. Once the new slab develops, more widespread storm slab activity can be anticipated.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 very real concern with ongoing reports of rider-triggering and sudden snowpack test result results. 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 touchy in some areas. Triggering this weakness would have nasty consequences, so be patient and don't be tempted by large, unsupported terrain.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

Continued snowfall and moderate winds are forming new wind slabs which may overlie existing reactive wind slabs. Watch for triggering in gullies, and in the lee of ridge crests and terrain breaks.

The recent snow may now be hiding windslabs that were easily visible before the snow fell.>Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 4th, 2014 2:00PM