Avalanche Forecast

Issued: Dec 11th, 2016 4:27PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada jlammers, Avalanche Canada

Forecast wind speeds are highly uncertain for Monday. If winds are strong, reactive wind slabs will form in exposed lee terrain, and the avalanche danger may be higher than posted.

Summary

Confidence

Low - Wind speed and direction is uncertain on Monday

Weather Forecast

Monday: Clear skies / Moderate northwest winds / Alpine temperature of -21Tuesday: Clear skies / Moderate northwest winds / Alpine temperature of -20Wednesday: Clear skies / Light northwest winds / Alpine temperature of -18

Avalanche Summary

In recent days, a few skier triggered wind slabs size to 1.0 were reported at treeline and in the alpine. If the wind picks-up on Monday, new wind slab activity will likely occur, especially in areas where snow surfaces are loose and unconsolidated.

Snowpack Summary

In most areas there is 30-50 cm of recent low density storm snow that has stayed unconsolidated except where it has been transported into wind slabs. The surface snow has been facetting due to the cold temperatures, and some surface hoar has been developing in isolated areas. The mid-pack has been reported to be well settled above above a crust that was buried in mid-november. This crust may be buried less than a metre to close to 2 metres deep, depending on elevation and previous exposure to winds. Snowpack tests on the crust have shown variable results from sudden and planar to no result. Professionals continue to monitor this crust and are watching for facet development above and below that may increase reactivity. The basal layers of the snowpack continue to be reported to be moist in some of the deeper snowpack areas of the region.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are reported to exist at treeline and in the alpine. If the winds pick-up from the north on Monday, new reactive wind slabs may form in unsuspecting locations. Watch for conditions that change with aspect and elevation.
Be cautious as you transition into wind affected terrain.Dig down to find and test weak layers before committing to a line.Avoid travelling in areas that have been reverse loaded by winds.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 12th, 2016 2:00PM

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