Avalanche Forecast

Issued: Dec 24th, 2017 4:46PM

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

Avalanche Canada jmcbride, Avalanche Canada

Looks like Santa's not quite ready to give up the goods just yet.  There should be a dusting of new snow for Christmas morning, and hopefully more to come near the end of the week.

Summary

Confidence

High - The weather pattern is stable

Weather Forecast

Light dusting (2-5 cm) of snow is expected late Sunday and early Monday morning.MONDAY: Mostly cloudy, flurries. Accumulation trace. Ridge wind light from the northwest. Temperature -3. Freezing level surface.TUESDAY: Mix of sun and cloud. Ridge wind light from the southwest. Temperature -4. Freezing level surface.WEDNESDAY: Cloudy, flurries. Accumulation trace. Ridge wind light to moderate from the west. Temperature -3. Freezing level surface.

Avalanche Summary

There have been no new reports of avalanche activity since last Wednesday when a natural Size 2 slab avalanche was reported on a southeast aspect at 1400 m on the North Shore mountains, as well as a Size 1 on a west aspect at 1200 m. Evidence of a natural cycle which likely occurred during or immediately after last week's storm was also reported in higher, alpine, terrain in the northern part of the region.

Snowpack Summary

Northerly winds have redistributed the recent storm snow scouring windward, northwesterly slopes and loading leeward southerly slopes in the alpine and exposed treeline areas. A thin sun crust can also be found on steep solar aspects. Approximately 15-30 cm of settled storm snow sits on top of the most recent December 18th melt-freeze crust, which has been unreactive in recent snowpack tests. Below this crusts lies 20 cm of well settled snow above the December 16th crust. Below this crust, a third crust, the 20 cm thick late-November crust, is now buried 40-50 cm. The lower snowpack well settled and moist to ground. Snowpack depths are about 135 cm at 1100 m elevation, with many early season hazards present at lower elevations.

Problems

Wind Slabs

An icon showing Wind Slabs
Northerly outflow winds have scoured windward aspects and formed wind slabs above the December 18th crust on leeward aspects in the alpine and in exposed areas at treeline.  It may still be possible for a human to trigger these slabs.
Watch for signs of instability such as whumpfing, or shooting cracks.Be cautious as you transition into wind affected terrain.Use caution in down wind (lee) areas. Wind loading may create pockets of wind slab.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 25th, 2017 2:00PM

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