Archived

Avalanche Forecast

Dec 27th, 2014–Dec 28th, 2014

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

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Sea To Sky.

Be alert to a developing wind slab problem.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Expect light snow on Sunday, then it becomes cold and clear with light to moderate N-NE outflow winds.

Avalanche Summary

On Friday a few size 1-1.5 wind slabs failed in steep terrain. On Wednesday, a snowboarder triggered a size 2-2.5 slab on a north aspect at 1900 m in the Callahan area. The crown was 10cm-100cm deep. The slab is believed to have failed on a crust. The snowboarder was buried, but was recovered safely by companion rescue.

Snowpack Summary

10-20cm new snow overlies large surface hoar crystals which sit above old wind slabs and other variable surfaces. A deeper layer of surface hoar buried in mid-December (now down 40-70cm) has been gradually gaining strength, but may still be a concern in some areas. The mid and lower snowpack contain several old crust layers, one of which may have been the failure layer for a recent burial (see avalanche summary).

Avalanche Problems

Storm Slabs

Be alert for wind slabs behind ridges and ribs. In more sheltered terrain, you could encounter storm slabs or loose sluff.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Be cautious as you transition into wind affected terrain.>Travel on ridgetops to avoid wind slabs on slopes below.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3