Archived

Avalanche Forecast

Mar 12th, 2016–Mar 13th, 2016

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

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

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

Avalanche Problems

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

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

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