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Avalanche Forecast

Dec 25th, 2014–Dec 26th, 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
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

Regions: Sea To Sky.

Tricky conditions may still exist in parts of the region.  Investigate the local stability in your riding area before committing yourself to avalanche terrain.

Confidence

Fair - Due to the number of field observations

Weather Forecast

A ridge of high pressure should keep the South Coast dry and mostly sunny on Friday. Freezing levels are expected to reach around 800m with light-to-moderate NW winds in the alpine. The next storm system is expected to reach the South Coast on Friday night. 5-10mm of precipitation are expected on Saturday with freezing levels reaching around 800m and light-to-moderate W-NW winds in the alpine. Sunday should be mostly sunny and dry with freezing levels around 500m.

Avalanche Summary

On Wednesday, a snowmobiler was involved in an avalanche in the Callaghan area.  Details are limited but it sounds like an isolated storm instability was the main problem. On Tuesday, several natural size 1 wind slabs were reported. On Friday, natural activity is not expected but isolated skier triggering remains possible, especially in areas where the surface hoar layer is still reactive. 

Snowpack Summary

A 40-60 cm persistent slab sits above the mid-December surface hoar layer. This layer appears to have gained strength and stabilized in most of the region but still may be reactive in the drier northeastern parts of the region. Reports suggest that the surface hoar is most prevalent on sheltered north aspect slopes at treeline elevation. Winds prior to burial likely destroyed the surface hoar in the alpine throughout most of the region. Strong SW winds during the storms created wind slabs which may still be a concern. The mid and lower snowpack contain several old crust layers but these have generally been unreactive.

Avalanche Problems

Persistent Slabs

An isolated surface hoar layer remains a concern in the northeastern parts of the region.  Look for this layer on sheltered north aspects slopes around treeline elevation. 
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3