Avalanche Forecast

Issued: Dec 4th, 2018 4:22PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet.

Avalanche Canada cgarritty, Avalanche Canada

Pack your sunglasses and watch for loose wet avalanche hazards increasing over the day.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Tuesday night: Clear. Light northeast winds. Building temperature inversion bringing 2000m temperatures above 0.Wednesday: Sunny. Light northeast winds. Alpine high temperatures around -1 with a lingering above freezing laver at about 1500-2000 metres.Thursday: Sunny. Light northwest winds. Alpine high temperatures around -1 with another above freezing layer hovering around 2000 metres.Friday: Sunny with cloud increasing over the day and flurries beginning in the evening. Light to moderate southeast winds. Alpine high temperatures around -2 with an above freezing layer at 2000 metres breaking down over the day.

Avalanche Summary

No new avalanches were reported over the past several days.Explosives control work in the Whistler area on Friday produced several size 1.5 cornice releases and one 20 cm deep size 1.5 storm slab. On Wednesday cornices were touchy; a size 1.5 cornice failure was initiated with a very light load. Control work produced storm slabs that averaged size 1.5 on a variety of aspects in the alpine. The outlier was a size 3 avalanche induced by control work on a north facing alpine feature which stepped down to the early November crust.Please submit any observations you have to the Mountain Information Network here,

Snowpack Summary

Days of cool, clear weather have grown a widespread new layer of feathery surface hoar crystals on the snow surface. Increasing sunshine and warmth are now expected to melt and replace this surface hoar with a new crust on steeper sun exposed aspects and mid elevations that see above freezing temperatures. Below the surface, the recent cold has been transforming last week's storm snow into a layer of faceted (sugary) snow. This layer of faceting storm snow increases in depth from about 20 cm at 1800-2000 metres, where it sits above a strong rain crust, to upwards of 30-40 cm in the alpine above 2000 metres, where the crust is not present. Here, the storm snow shows good signs of bonding well to the now well-settled mid snowpack.Above 2000 m, about 50-150 cm of snow now sits on the early November melt-freeze crust. This crust may be layered with weak faceted crystals in places where it lies close to the ground. This is most likely to cause problems in glaciated terrain or on smoother, high elevation slopes where the summer snow did not melt out.

Problems

Loose Wet

An icon showing Loose Wet
Warm temperatures and strong sunshine will destabillize surface snow and promote loose wet avalanche activity on sun-exposed slopes on Wednesday. Loose wet slides may occur naturally or with a human trigger.
Be aware that low angle December sun tends to target steeper slopes.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Dec 5th, 2018 2:00PM