Avalanche Forecast

Issued: Mar 24th, 2012 11:34AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Loose Wet, Cornices and Deep Persistent Slabs.

mpeter, Avalanche Canada

Kootenay Boundary.

This is the first big warm-up after some significant snowfall. A warming-related avalanche cycle is expected.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Sunday: Expect clouds to build through the day, with freezing levels reaching 2500m under light southerly winds. Monday & Tuesday: Continued clouds with light flurries possible. Winds remain light southerly and freezing levels may reach 1500m.

Avalanche Summary

We have reports of loose, moist avalanches being triggered by solar radiation on sunny slopes. A fatal avalanche incident occurred in this region on Wednesday. We will post more details when they become available.

Snowpack Summary

The warm temperatures have brought us into a spring melt freeze cycle with the surface snow softening with daytime warming on solar aspects then crusting overnight as temperatures dip back below freezing. On north aspects, the surface snow remains cold. Up to 60 of recent storm snow is settling quickly with the warm temperatures and this most recent storm interface is gaining strength. The early February surface hoar lingers, down 100-180cm. Although the avalanche activity has become more sporadic on this layer, triggering it would yield a very large destructive avalanche.

Problems

Loose Wet

Warm temperatures and solar radiation are triggering wet sluffs. These small avalanches may trigger the deeper weaknesses.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Cornices

Cornices are very large and may fail with daytime warming. There is potential for triggering deep slabs on underlying slopes.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 6

Deep Persistent Slabs

The deep nature of the mid-February surface hoar layer makes potential avalanches triggered on this layer large and destructive. Avoid thin snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 8

Valid until: Mar 25th, 2012 9:00AM