Avalanche Forecast

Issued: Mar 12th, 2016 8:00AM

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

Parks Canada andrew jones, Parks Canada

Lingering instabilities and real overhead hazard requires continued caution and safe travel techniques.

Summary

Weather Forecast

Unsettled weather with clouds, scattered flurries and rain at lower elevations. Freezing levels rising to 1800m this afternoon, winds S 25-40 and up to 4cm of accumulation. Freezing levels drop tonight with a cold front and up to 6cm of snow with strong S winds. Light precipitation continues through Monday with high pressure later in the week.

Snowpack Summary

Wind slabs are widespread in the alpine and treeline. Warm temps and strong sun formed surface crust below 1700m and on solar aspects. Several crusts are present in the upper snowpack. Feb 27 is down 50-70cm is most reactive where SH overlies a sun crust. Feb 10 is down 100-120 and reactive in isolated locations. Well settled & strong below.

Avalanche Summary

Skier partially buried after triggering a wind slab below Illecillewaet Glacier. Cornice failures triggered slabs on a NW asp, sz 1.5 to 2.5. Cornice and icefall triggered sz 2.5 and sz 3.0 slabs in the Asulkan drainage, below Mt Leda. A cornice triggered a sz 4 avalanche failing to glacial ice on the N facing slopes of Parsons Peak (Loop Brook).

Confidence

Problems

Persistent Slabs

An icon showing Persistent Slabs
The Feb 27th interface is down 60cm and is producing sudden planar results on a crust on S though W aspects. Test results on NE aspects showed stubborn results. Wind-loading will increase it's sensitivity. Wet slabs below treeline from rain.
Be aware of the potential for wide propagations.Dig down to find and test weak layers before committing to a line.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs
Wind slabs are widespread and reactive in the alpine and treeline. A skier was partially buried yesterday after triggering a wind slab on a relatively small feature. When triggered in open slopes, wind slabs may step down to deeper persistent layers.
If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Cornices

An icon showing Cornices
The additional storm snow, accompanied by SW winds and mild temp's, has allowed cornices to grow and become fragile. Limit your exposure to these overhanging beasts along the ridge crests. A cornice triggered avalanche on Parsons Peak dug down to ice
Give cornices a wide berth when travelling on or below ridges.Pay attention to overhead hazards like cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Mar 13th, 2016 9:00AM