Archived

Avalanche Forecast

Dec 29th, 2017–Dec 30th, 2017

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

Regions: Sea To Sky.

Natural avalanche activity is expected to tapper off early Saturday morning, but human triggered avalanches remain possible or even likely in wind loaded features, especially those that are steep and unsupported.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

One last blast of Pacific moisture is set to clash with the Arctic air mass over the province as a low pressure system moves towards the Lower Mainland late Friday. As was the case with Thursday's storm, alpine precipitation will fall as snow with only the North Shore Mountains at risk of seeing some liquid precipitation creeping up the slopes as warm air associated with the low just clips the Lower Mainland.FRIDAY NIGHT: Freezing level at valley bottom, 10 to 30 cm of snow possible, moderate southwest wind.SATURDAY: Skies clearing throughout the day, freezing level at valley bottom, light to moderate northwest wind, trace of snow possible.SUNDAY: A few clouds, freezing level at valley bottom, light variable wind, no snow expected.MONDAY: Scattered cloud cover, freezing level at valley bottom, light variable wind, no snow expected.

Avalanche Summary

On Thursday control work produced soft storm slabs to size 1.5 with crowns up to 45cm in depth. Natural avalanches to size 1.5 were also reported.

Snowpack Summary

Thursday's storm delivered 15 to 35 cm of new snow accompanied by moderate to strong winds out of the south/southwest. The new snow covers a medley of old surfaces which include stubborn old wind slabs and wind-scoured exposed crust in the alpine, and soft unconsolidated snow in sheltered areas at treeline and below. 20 to 60 cm below the surface you'll likely find a widespread melt-freeze crust that was buried on December 15th. This layer has not produced much in the way of avalanche activity, but could come to life with the additional load of new snowfall, especially in areas where loose facets exist above the crust.Beneath the December 15th layer, the lower snowpack is generally strong and well settled.

Avalanche Problems

Storm Slabs

Any natural activity induced by Friday night's storm should quickly taper off Saturday morning, but you need to remain vigilant in your travel practices, especially when it comes to avoiding convexities, terrain traps and wind loaded slopes.

Avoid wind loaded pockets at and above treeline, especially those near ridge crests and roll-overs.Avoid large convexities and steep unsupported slopes.The new snow could use a day to settle and stabilize before we start to tee up the bigger lines.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2