Archived

Avalanche Forecast

Dec 9th, 2015–Dec 10th, 2015

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Northwest Inland.

The places you are going to find the best riding conditions in the wake of the storm are probably the same places where the danger from a layer of buried surface hoar is greatest.

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

THURSDAY: light snowfall, and moderate easterly winds, freezing levels at the valley floor. FRIDAY: flurries, light to moderate southerly winds, freezing levels at the valley floor. SATURDAY: There is some uncertainty in the forecast track of the storm that should hit the coast on Saturday. Some models have it coming in further north which could bring snow to the NW Inland others have it missing the region entirely.

Avalanche Summary

It sounds like there were touchy conditions out there over the weekend. Reports of some large skier triggered and skier controlled avalanches from tree-line suggest that the load on the recently buried surface hoar is probably at a critical level.

Snowpack Summary

By my reckoning up to 60cm of new snow has fallen since the weekend with the area around Smithers receiving the greatest amounts. Unfortunately, heavy rain fell below 1500m and probably formed a rain crust that can be found just below the surface at lower elevations. At higher elevations the new snow sits on a layer of surface hoar, which has the potential for remote triggering, wide propagations and prolonged sensitivity to triggers. It has been reported lurking in most sheltered areas at tree-line and below, although I suspect that it may exist well into the alpine.

Avalanche Problems

Storm Slabs

Weaknesses are lurking within and under the recent storm snow with particularly touchy slabs on the leeward side of ridge crests and on steep unsupported slopes.

Use caution in areas that are being reverse loaded by winds.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 2 - 5

Persistent Slabs

The new snow sitting on a buried layer of surface hoar may be reaching a critical depth for avalanches.

Avoid open slopes and convex rolls at tree-line and in the alpine where buried surface hoar may be preserved.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 5