Avalanche Forecast

Issued: Nov 26th, 2016 3:03PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Cornices.

Avalanche Canada jlammers, Avalanche Canada

The region has just received well over a metre of snow, and destructive avalanches are still a real possibility. Give the snowpack time to gain strength before pushing into steep terrain.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Sunday: 5-15cm of new snow / Moderate to strong southwest ridgetop winds / Freezing level at 900m. Monday and Tuesday: Mix of sun and cloud / Light and variable winds / Freezing level at about 900m

Avalanche Summary

In recent days, widespread storm slab avalanche activity was triggered naturally or with explosives. Most of the avalanches observed were in the size 2 range; however, a few size 3 and 3.5 avalanches were observed running in large, lee alpine features. With ongoing snow and wind on Saturday and Sunday afternoon, I'd be on the look-out for continued destructive storm slab activity, especially in higher elevation lee terrain.

Snowpack Summary

With ongoing stormy weather, snow depths have increased rapidly over the past week bringing treeline snow depths to 180-220 cm. Much of the snow from Wednesday and Thursday has settled and gained significant strength. That said, more recent systems have created large and reactive storm slabs which appear to be especially touchy in higher, wind-exposed terrain. Over a metre below the surface you'll find the thick mid-November crust. The reports we've received suggest a reasonable bond at this interface. Below this, the snowpack is reported to be strong and well-consolidated. A significant change from even a week ago is that we are now above threshold for avalanches below treeline (think cutblocks and open areas in the forest), so heads up as you work your way towards treeline. Nice to see mid-week posts to the Mountain Information Network... all observations are useful so please keep 'em coming!

Problems

Storm Slabs

An icon showing Storm Slabs
Even if the storm tapers-off on Sunday, storm slabs may remain touchy, especially on higher elevation, wind-exposed features. I'd give the snowpack time to settle and gain strength before pushing into steeper terrain.
Be cautious as you transition into wind affected terrain.Stay off recent wind loaded areas until the slope has had a chance to stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Strong winds and heavy snowfall have been the perfect combo for large cornice development. To avoid a nasty ride, give fresh cornices a wide berth while traveling on ridgetops.
Extra caution needed around cornices with current conditions.Stay well to the windward side of corniced ridges.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 27th, 2016 2:00PM

Login