Avalanche Forecast

Issued: Mar 7th, 2014 8:00AM

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

Parks Canada danyelle magnan, Parks Canada

This weekend an intense storm is forecast. Heavy precipitation, with rising freezing levels and strong winds, will increase danger. A widespread natural avalanche cycle is expected, with large avalanches running to valley bottoms.

Summary

Weather Forecast

There will be a brief break in the storms today, before an intense and moisture laden front hits this weekend. Today will be mostly cloudy with flurries. The alpine high is -2 and winds will be moderate but gusty from the SW. Sat and Sun are forecast to get up to 20cm a day, with freezing levels rising to 1600m by Sunday and strong  SW winds.

Snowpack Summary

Up to 60cm of heavy snow over light snow has created a touchy soft slab. This lies on top of suncrusts on solar aspects, and windslab on N and E aspects. The new slab is failing with easy to moderate results within the new snow, as well as at the old interface. The Jan 28/Feb 10 PWL is down 1.2-1.5m under a cohesive slab.

Avalanche Summary

Artillery control over the past few days produced avalanches to size 3.5 running fast and to the end of their run-outs. Adjacent to the park, an avalanche on the Feb 10 PWL was 1.5m deep and up to 200m wide. Reports also indicate that the storm slab is becoming reactive to skier traffic on steep convex features.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs
Warming temps through the storm created a punchy storm slab that is sitting on a variety of weak surfaces. Avalanche control proved that this slab is reactive and produced large avalanches. The slab may be more reactive in wind-exposed terrain. 
Choose well supported terrain without convexities.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
This last storm, and the forecast dump of snow this weekend, may wake a weak persistent layer up. This layer, buried ~1.5m deep, is still reactive in snowpack tests and if triggered will produce very large and destructive avalanches.
Be aware of thin areas that may propogate to deeper instabilites.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Mar 8th, 2014 8:00AM