Avalanche Forecast

Issued: Nov 22nd, 2016 3:38PM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs and Storm Slabs.

cam_c, Avalanche Canada

Purcells.

Danger is expected to increase with forecast snow and wind. As always, and especially when forecast confidence is low, it's important to supplement this forecast with your own observations. Please post your obs to the MIN.

Summary

Confidence

Weather Forecast

Light snowfall starting early Wednesday morning is expected to continue throughout Wednesday with 5-10cm of fresh snow by Wednesday evening, especially in the northern part of the region. Moderate southerly ridgetop winds are expected at the onset of the storm before shifting to light to moderate southwesterlies for Wednesday. Another moderate system is expected to impact the area on Thursday, with a stronger system expected on Friday. Daytime high freezing levels are expected to rise from around 1300 m on Wednesday to above 1500 m on Friday.

Avalanche Summary

No recent avalanches have been reported in this region.

Snowpack Summary

Recent reports suggest snowpack depth is 80-150cm in the alpine and 60-100cm at treeline. The snowpack below treeline remains below threshold for avalanches, but watch out for early season hazards such as hidden rocks, stumps, and open creeks. Up to 40cm of recent storm snow is settling into a cohesive slab over a hard crust. This crust is the primary weakness of concern and is expected to become increasingly reactive as the slab above settles and stiffens. Southerly winds have also formed very touchy wind slabs on lee features below ridetops in exposed terrain. Although conditions have been reported as being quite good, remember that an early season snowpack is inherently weak and requires thorough investigation before stepping out into bigger terrain.

Problems

Wind Slabs

Touchy fresh wind slabs are primed for triggering on the downwind side of ridgecrests in exposed areas.

Avoid steep or convex lee features directly below ridgetops.Avoid areas where the snow feels stiff or 'slabby'.Travel on ridgetops to avoid wind slabs on slopes below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Storm Slabs

Recent storm snow is beginning to settle into a cohesive slab that is bonding poorly to a hard crust. On steep slopes the powder is also sluffing readily.

Carefully assess the bond to the crust before committing to a slope.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Nov 23rd, 2016 2:00PM