Avalanche Forecast

Issued: Apr 1st, 2012 10:27AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Monday: heavy snowfall continuing overnight into Tuesday - strong to extreme southwest winds - freezing level at 1300m Tuesday: continued heavy snowfall - strong southwest winds decreasing throughout the day- freezing level at 1000m Wednesday: a mix of sun and cloud as a clearing trend develops - light and variable winds - freezing level at 900m

Avalanche Summary

Explosives control on Saturday produced numerous size 1.5-2 avalanches that ran on the March 26th interface. Some of these avalanches ran sympathetically with other slides, or remotely at distances of up to 300m. On the same day, a size 2 skier-triggered windslab avalanche occurred on a southwest aspect at treeline in the Fitzsimmons Range. On Sunday, ski cutting produced numerous size 1-1.5 windslab avalanches that ran within snow that fell over the previous 24hrs. Expect widespread wind and storm slab avalanche activity with potential to step down to the deeper March 26 interface with weather forecast for Monday.

Snowpack Summary

10-15cm of new snow has added to the 75-100cm that overlies surfaces that were buried on March 26. This interface consists of a crust which exists on all aspects except true north facing slopes at treeline and in the alpine, where small surface hoar may be present in sheltered places . This week's snow continues to be redistributed by consistently moderate to strong variable winds, forming windslabs in unsuspecting locations. Below the March 26 interface, the snowpack is well settled and bonded, with further strength gains deeper in the pack. Cornices are huge, and will continue to grow with the forecast weather pattern.

Problems

Wind Slabs

An icon showing Wind Slabs
Forecast strong to extreme winds and heavy snowfall will form reactive and potentially destructive new wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 5

Storm Slabs

An icon showing Storm Slabs
Forecast heavy snowfall will add to an ongoing storm slab problem. Storm slabs may be more destructive than usual, especially if they fail on weak layers buried on March 26th.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 6

Cornices

An icon showing Cornices
Cornices are very large, potentially unstable and will continue to grow with forecast weather.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 6

Valid until: Apr 2nd, 2012 9:00AM