Archived

Avalanche Forecast

Mar 19th, 2015–Mar 20th, 2015

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

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Inland.

Wind slabs may keep building, even if snowfall amounts are not great.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Light snow is expected on Friday, Saturday and Sunday (a few cm each day). Winds are moderate to strong, mainly from the south. The freezing level should be near 1900 m on Friday, dropping to 300 m on Saturday.

Avalanche Summary

On Monday, a skier triggered a size 2 wind slab on a NE aspect at 1300 m. Several loose avalanches also failed on steep sunny slopes. Click on the blue dot on the map to see a recent wind slab that may have failed naturally or remotely in Sinclair. It was a thick, hard wind slab on a north aspect. There are likely to more like this lurking. More snow and wind will likely promote further wind slab activity.

Snowpack Summary

New snow will be landing on recently formed wind slabs and wind-scoured surfaces. Weaknesses buried in the upper snowpack include hard crusts, surface hoar, and/or surface facets. At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile. Below treeline, the snow appears to be in a spring melt-freeze cycle.

Avalanche Problems

Wind Slabs

Forecast wind and snow is expected to form fresh and reactive wind slabs. Watch for triggering in gullies and in the lee of ridge crests.

Be cautious as you transition into wind affected terrain.>Give cornices a wide berth when travelling on or below ridges.>Travel on ridgetops to avoid wind slabs on slopes below.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4