Avalanche Forecast

Issued: Feb 23rd, 2014 7:49AM

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

swerner, Avalanche Canada

Kootenay Boundary.

Don't let the improving weather lure you into high risk scenarios. Check out the Forecasters Blog post for the Kootenay Boundary.The hazard will increase on the first day of full sun.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The high off the north coast will continue to push modified arctic air across the region. Some unstable disturbances are embedded in this flow, bringing scattered cloud along the southern boundary of the region. Most other locations further north will see sun. Monday: Mix of sun and cloud. Treeline temperatures near -8.0. Ridgetop winds light from the north.Tuesday: Sunny. Treeline temperatures near -3.0. Ridgetop winds light from the northeast.Wednesday: Mostly sunny. Treeline temperatures -2.0. Ridgetop winds light from the west. Freezing levels rising to 1200 m.

Avalanche Summary

On Sunday, a skier triggered size 2.5 was reported. Party of three with two involved, no burials. The crown was near 100 cm deep and released near ridgetop in storm snow and then stepping down to the persistent weak interface. Remote triggering and long fracture propagations are occurring on all aspects and elevations. With forecast sun, the avalanche hazard will likely increase on solar slopes.Check out the Forcaster Blog! It shows a photo of a remote triggered size 3 last Friday in the southern part of the Kootenay-Boundary.

Snowpack Summary

Moderate SW winds have loaded leeward and cross-loaded exposed slopes. Changing winds from the north may build fresh wind slabs on southerly slopes. There is over a metre of recent storm snow that is sitting on a weak layer that is a mixture of facets, surface hoar, melt-freeze crusts and any combination of these. The weak layer is widespread at all elevations and aspects and continued whumpfing and avalanche activity is reported. The storm slab continues to settle and become more cohesive allowing for longer fracture propagations and remote triggering from up to 200 m away, yikes! This persistent weak layer is expected to be a concern for some time; at all elevations and aspects. Treeline and below treeline is catching a lot of people by surprise. With forecast sunny periods, solar aspects will likely become more reactive.

Problems

Persistent Slabs

Expect the deeply buried weak layers to continue to produce large and destructive avalanches. Slopes are primed for human triggering and remain a concern on all aspects and elevations.

Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.>Use conservative route selection and resist venturing out into complex terrain, even if you observe no obvious signs of unstable snow.>Avoid areas with overhead hazard, especially on solar aspects.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 6

Wind Slabs

Wind has transported snow and built fresh, touchy wind slabs. Be aware of weak cornices looming over slopes. If they fail, they will likely trigger a large slab avalanche on the slope below.

Extra caution needed around cornices with current conditions.>Avoid freshly wind loaded features.>Caution in lee and cross-loaded terrain near ridge crests.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Feb 24th, 2014 2:00PM