Avalanche Forecast

Issued: Mar 31st, 2015 8:03AM

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

percy woods, Parks Canada

Glacier.

Summary

Weather Forecast

More warm precipitation is expected through the day today and into tonight. Below treeline this precipitation will likely be in the form of rain with moist snow at treeline and above. Upwards of 10cm of snow is expected at higher elevations.

Snowpack Summary

Over 30cm of heavy wet snow mixed with rain have fallen at 2000m over the last three days. This will be overloading the sandwich of snow and crust layers that have been the story of this winter's snowpack. Expect this storm snow to be overloading the persistent weak layers in the top 1.5m making it reactive to skier triggering.

Avalanche Summary

Numerous loose wet snow avalanches through the highway corridor yesterday ranging from size 1.5 to 3. Of note was a glide crack release off the north side of Mount MacDonald.

Confidence

Timing of incoming weather systems is uncertain

Problems

Persistent Slabs

Continued warm precipitation has been enough to begin to overload the various persistent instabilities in our snowpack. A series of weak layers in the top 1.5m of snowpack should be considered triggerable by back country riders.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Storm slabs should be expected at tree line elevations and above in the immediate lee of ridge lines and crossloaded features. These slabs are lying over a number of crust and weak layer sandwiches that were previously reactive to skier triggering.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Widespread loose wet avalanches have been occurring in the highway corridor and should be expected in the back country at and below treeline.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 1st, 2015 8:00AM