Archived

Avalanche Forecast

Dec 7th, 2016–Dec 8th, 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

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast Inland.

Caution as you transition into wind exposed terrain, as lingering wind slabs may be reactive. Please share your observations on the Mountain Information Network (MIN).

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

THURSDAY: Sun and cloud, moderate to strong east winds, alpine temperatures at -15.FRIDAY: Flurries with 5-15 cm of new snow, moderate southwest winds, alpine temperatures at -12.SATURDAY: Flurries with 5 cm of new snow, moderate southwest winds, alpine temperatures at -10.

Avalanche Summary

No new avalanches were reported on Tuesday, but previous reports include natural size 1 storm slabs in steep rocky terrain and in the lee of a ridgetops. Wind slabs may remain reactive on wind loaded features at higher elevations, or where they sit over preserved surface hoar.

Snowpack Summary

Storm snow from the past weekend is gradually settling throughout the region. Storm snow totals in the Coquihalla area were 40-60 cm, while northern parts of the region only received 10-30 cm. Storm snow instabilities appear to be settling out, with the greatest potential for triggering in wind affected terrain at higher elevations. Surface snow has begun to facet and soften with the cold air temperatures, and will likely create a weak interface when the next storm arrives. Buried surface hoar layers have been reported in the northern part of the region, including a 30 cm deep layer at treeline in the Duffey area that was reactive to skier triggering on the weekend, and a 60 cm deep layer in the Pemberton area. There is no recent information on the reactivity of these layers. A widespread crust can be found 70-100 cm deep throughout the region. Although this layer has been unreactive in recent snowpack tests, cold temperatures will promote facet growth around the crust and make it possible to trigger this layer in shallow wind-affected starts zones.

Avalanche Problems

Wind Slabs

Watch for wind slabs in the lee of ridgetops and in places where surface hoar may be preserved. Wind slabs may exist on any aspect, as winds have shifted from the southwest to the northeast.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2