Avalanche Forecast

Issued: Dec 18th, 2018 4:30PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs and Persistent Slabs.

mbender, Avalanche Canada

South Coast Inland.

A brief break between storms on Wednesday. Expect avalanche danger to rise on Thursday as another Pacific frontal system impacts the region.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Thursday

Weather Forecast

TUESDAY NIGHT: Flurries, accumulation 5-10cm. Alpine temperature -4. Moderate to strong southwest wind. Freezing level 1100m. WEDNESDAY: Scattered flurries, accumulation 5 cm. Alpine temperature -2. Light west wind. Freezing level 1300m. THURSDAY: Heavy snowfall, accumulation 20-30 cm. Alpine temperature -1. Moderate to strong southwest wind. Freezing level 1500m. FRIDAY: Cloudy with sunny breaks. Alpine temperature -5. Light west wind. Freezing level 300m.

Avalanche Summary

There was a report of natural avalanche in the Duffy Lake area on Monday. This appears to be a size 2 that was 60 cm thick and 80 m wide on a southeast slope at tree line. Click here to see the MIN post.

Snowpack Summary

Another storm has brought an additional 20-30cm of snow to the region at upper elevations. Strong southerly winds have distributed new snow into variable wind slabs in exposed locations.Below the recent storm snow lies a weak layer, comprising 20-30 cm of low density faceted snow. Initially, the snow did not bond well to this layer. While it's likely gaining strength, field observations show that slab avalanches remain possible on this layer.Near the base of the snowpack, a crust exists that previously had sugary facets. This could potentially still be of concern in high north facing areas in drier parts of the region. Elsewhere, this layer is no longer a concern.

Problems

Wind Slabs

New snow combined with wind has developed fresh wind slabs in the lee of terrain features.

Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: North, North East, East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

A weak layer buried approximately 70 cm below the surface has the potential to produce large avalanches.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Dec 19th, 2018 2:00PM