Archived

Avalanche Forecast

Dec 9th, 2016–Dec 10th, 2016

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Coast.

Heavy snowfall this weekend will create very dangerous avalanche conditions.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

SATURDAY: 15-30 cm of new snow, 20-40 km/h southwest winds, treeline temperatures -2.SUNDAY: 5-10 cm of new snow, light west winds, treeline temperatures -2.MONDAY: Sun and cloud, light northwest winds, treeline temperatures -5.

Avalanche Summary

On Thursday, avalanche activity was limited to minor sluffing in steep terrain. With heavy snowfall and strong winds in the forecast, widespread storm slab activity can be expected for the weekend.

Snowpack Summary

Forecast snowfall amounts are uncertain, but expect 20-40 cm of fresh snow by Saturday afternoon. The new snow is falling on a variable surface that includes settled snow on southerly aspects, loose snow on shaded aspects, isolated pockets of surface hoar, and sun crusts on steep solar aspects. Overall the incoming snow will likely bond poorly to this interface. The thickest and most touchy storm slabs can be expected on north-facing wind-loaded features. A rain crust exists 30-50 cm deep, and recent reports suggest the storm snow may still be poorly bonded to the crust on shady north aspects. Below the crust, the snowpack is settled and strong. Total snowpack depths are 160-200 cm at treeline.

Avalanche Problems

Storm Slabs

Fresh storm slabs will build throughout the weekend. Storm snow is falling on weak and unsettled snow, which will make the storm slabs very reactive to human triggers.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid avalanche terrain during periods of heavy loading from new snow and wind.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Very Likely

Expected Size: 2 - 3