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Avalanche Forecast

Dec 25th, 2016–Dec 26th, 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
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: Sea To Sky.

Moderate danger on Monday hinges on snowfall arriving late in the day. Look to Tuesday's forecast if snow is piling up around you.

Confidence

Moderate - Timing of incoming weather systems is uncertain on Monday

Weather Forecast

Monday: An incoming storm will deliver 15-25cm of new snow, intensifying in the evening. Winds will be strong from the southwest. Freezing level to 700 metres with alpine temperatures near -7.Tuesday: Continuing snow with 10-15cm accumulating. Winds moderate gusting to strong from the southwest. Freezing levels rising to 1000 metres with alpine temperatures of -6.Wednesday: Lingering flurries delivering 5-10cm of new snow. Winds moderate gusting to strong from the southwest. Freezing levels dropping to 800 metres with alpine temperatures of -9.

Avalanche Summary

Recent reports include a natural size 2 cornice release from an northwest aspect in the upper Soo area. Ski cuts and skier traffic continue to produce size 1 avalanches in isolated pockets of wind slab as well as size 1 loose dry avalanches in steep terrain. A MIN report from Saturday in the Pemberton Icefield area neatly demonstrates the potential for wide slab propagations on wind loaded features.

Snowpack Summary

Snowfall from Thursday and Friday deposited 5-20cm of new snow on the surface. Strong winds have continued to redistribute 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 these surfaces 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

Pockets of wind slab are lingering in lee terrain and remain sensitive to human triggers. New snow and strong winds will be piling on fresh slabs toward the end of the day on Monday.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Minimize exposure during periods of heavy loading from new snow and wind.New snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2