Avalanche Forecast

Issued: Mar 8th, 2014 7:30AM

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

Peter, Avalanche Canada

Northwest Inland.

Recent snowfall amounts vary significantly throughout the region. Areas that received less than 20 cm of new snow may see slightly lower avalanche hazard.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Tonight and Sunday: Periods of snow 5-15 cm. The freezing level is around 800-1000 m. Winds are strong easing to moderate from the W-SW. Monday: Cloudy with sunny breaks and possible flurries. The freezing level is around 1000 m. Winds are light but gusty from the W-SW. Tuesday: Periods of snow. The freezing level is around 1500 m and winds increase to strong from the SW.

Avalanche Summary

Reports suggest that a natural avalanche cycle most likely started overnight on Friday - at least in areas that received over 20 cm of new snow. Avalanches up to size 3 were expected. Most of these probably released on the recently buried snow surface, but some may have stepped down to the mid February layer.

Snowpack Summary

Up to 40 cm of dense storm snow now sits on a layer of surface hoar and/or a thick layer of facetted snow on shady slopes at all elevations, a sun crust on steep solar aspects, and various wind affected surfaces in exposed terrain. Strong southwest winds have created dense wind slabs on exposed lee slopes and in cross-loaded features. The early February weak layer of facets, crusts, and surface hoar is buried down about 50-100 cm. This layer could become reactive in the next couple days with additional loading and significantly warmer temperatures. Basal facets and depth hoar remain a concern in areas with thin or variable snow cover.

Problems

Storm Slabs

Snowfall amounts vary throughout the region. Some areas now have over 40 cm of dense storm snow overlying a weak layer of facets and/or a crust. Dense wind slabs are also likely in NW-E facing terrain at and above treeline.

Choose well supported terrain without convexities.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Persistent Slabs

A weak layer buried in mid-February is now down 60-120 cm deep. Triggering an avalanche on this layer would result in a very large and destructive avalanche.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid lingering in runout zones.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Mar 9th, 2014 3:00PM