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Avalanche Forecast

Dec 23rd, 2016–Dec 24th, 2016
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
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

Regions: Sea To Sky.

Recent storms have set up great skiing for the holiday weekend, but don't overlook the wind slab problem that still exists at upper elevations.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Saturday: Mix of sun and cloud with no new snow. Winds light from the northeast. Freezing level to 400 metres with alpine temperatures to -9.Sunday: A mix of sun and cloud with a trace of new snow. Winds light from the west. Freezing level to 200 metres with alpine temperatures to -9.Monday: Heavy snowfall delivering up to 30cm of new snow. Winds strong from the southwest. Freezing level rising to 700 metres with alpine temperatures to -6.

Avalanche Summary

Recent reports include both skier-triggered and natural size 1 avalanches from isolated start zones and convex features. Reports from Wednesday in the region show explosives triggering wind slabs up to size 1.5 in the alpine.

Snowpack Summary

A light snowfall from Thursday deposited 5-10cm of new snow on the surface. Strong winds overnight caused redistribution of this snow in high elevation and wind exposed areas. Where it hasn't blown away, the new snow lies above a variety of hard surfaces that may include sastrugi, wind crust and hard wind slab. Strong to extreme winds formed this surface and caused significant wind redistribution of the underlying storm snow from earlier this week. This 30-50cm of storm snow overlies a variable snow surface from last week that includes either weak faceted snow or surface hoar in sheltered areas at treeline and below. The widespread mid-November crust is buried 1-2m deep in the snowpack. Recent snowpack and explosive tests have shown the crust to be unreactive, but it could remain a problem in shallow alpine start zones.

Avalanche Problems

Wind Slabs

Wind slabs remain an issue to be managed with ongoing observation and careful evaluation. A thin layer of new snow may be masking buried wind slab.
Dig down to find and test weak layers before committing to a line.Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2