Avalanche Forecast

Issued: Jan 30th, 2018 5:57PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Cornices.

Avalanche Canada cgarritty, Avalanche Canada

Seek out sheltered snow that hasn't been pressed or redistributed into stiff slabs by recent winds. Deep and unsupported deposits will remain unstable over the short term.

Summary

Confidence

Moderate -

Weather Forecast

Wednesday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Alpine high temperatures around -9 in the north of the region and -5 in the south.Thursday: Cloudy with scattered flurries and 2-5 cm of new snow, increasing overnight. Moderate southwest winds. Alpine high temperatures around -5.Friday: Cloudy with scattered flurries and 2-5 cm of new snow. Possible higher accumulations in the south of the region. Moderate to strong southwest winds. Freezing level rising to 1500 metres with alpine temperatures around -1.

Avalanche Summary

No new avalanches were reported in the region on Monday.Reports from Saturday and Sunday showed recently formed storm slabs reactive to skier traffic and ski cutting, producing numerous small (Size 1, 20-35 cm deep) storm slab and loose dry releases. Observations from the north of the region on Monday showed especially touchy conditions, with numerous soft storm slabs releasing very easily on terrain over 35 degrees.

Snowpack Summary

Monday's continuing storm brought 20-40 cm of new snow to the surface above about 1700 metres with depths that increase with elevation. The greatest accumulations occurred in the south of the region. The snowpack at lower elevations is now capped by a new rain crust and only light new snow amounts. At higher elevations, strong southerly winds have been redistributing the new snow deep deposits and cornices in leeward terrain. Including the new snow, storm snow totals since mid-January have reached about 150 cm.Below this depth, you'll begin find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the more well-documented mid-December crust layer. Persistent slab avalanche activity from the Whistler area late last week suggests that heavy triggers like a large storm slab or cornice release may carry the risk of triggering this layer in isolated terrain - particularly in the north of the region where it has shown prolonged reactivity in snowpack tests.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall and intense winds created thick new storm slabs during the storm. The new snow's bond to the surface is gradually improving, but slabs may remain reactive to human triggering in steep terrain and around variable wind deposits
Be aware of the potential for wide propagations due to the presence of hard windslabs.Watch for slabs to trigger more easily in thin spots near deep wind-loaded deposits.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Cornices

An icon showing Cornices
Heavy snowfall and and high winds have built fragile new cornice growth.
Falling cornices may trigger large avalanches on slopes below.Give cornices a wide berth when traveling on or below ridges

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Jan 31st, 2018 2:00PM

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