Avalanche Forecast

Issued: Mar 20th, 2015 9:12AM

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

Avalanche Canada swerner, Avalanche Canada

Snow, rain and strong wind combined with buried weak layers make the perfect recipe for avalanches. Check out the new Forecasters Blog @ avalanche.ca.

Summary

Confidence

Good

Weather Forecast

Is spring the new winter? Waves of precipitation will continue overnight Friday and into Saturday. Saturday will see precipitation amounts 5-15 mm, ridgetop winds moderate from the SW and freezing levels 1500-1700 m. A dry day with a mix of sun and cloud is forecast on Sunday as the Pacific ridge crosses the province. Monday will see somewhat cooler temperatures with freezing levels near 1100 m and light precipitation 3-10 mm. Unsettled conditions will continue as a series of fronts and ridges move across the region next week.

Avalanche Summary

On Thursday, numerous size 1-2 storm slabs and loose dry avalanches up to 1.5 were reported. Wednesday, several natural slab avalanches and skier triggered avalanches up to size 2 were reported. Most of these avalanches failed on north- easterly aspects above 2000 m. With forecast snow, rain and wind, natural avalanche activity is expected to continue tomorrow.

Snowpack Summary

At higher elevations, up to 20-50 cm of snow sits over a plethora of old surfaces including wind affected surfaces, and/or old wind slabs and crusts which were buried mid-March. Previous strong winds have redistributed new snow into wind slabs on leeward terrain features and lower elevations (below 2000 m) are sporting spring-like, melt-freeze conditions. Digging deeper (40-70 cm below the surface) sits the mid-February facet/ crust interface. This interface has not been as reactive in the South unlike regions to the North. However, it is alive and well in test profiles. It may just require additional load and/ or a change in slab properties before it reaches threshold and becomes reactive. The late-Jan crust/surface hoar layer (around 1m deep) and the mid-January surface hoar (around 1.5m deep) have been dormant for several weeks.

Problems

Storm Slabs

An icon showing Storm Slabs
Touchy storm slabs continue to build and sit over a weakness from mid-February that seems to be stubborn. However; slabs failing on this layer will have larger destructive potential.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Loose Wet

An icon showing Loose Wet
Steady rain and warming at lower elevations will saturate and weaken the snowpack. Overhead hazards like cornices are weak and could trigger slabs from slopes below.
Avoid exposure to terrain traps where the consequences of a smaller, wet and heavy avalanches could be serious.>Watch for clues, like natural avalanche activity, sluffing off of cliffs, and snowballing that the snowpack deteriorating. >

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 21st, 2015 2:00PM