Avalanche Forecast

Issued: Jan 6th, 2017 4:45PM

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

shorton, Avalanche Canada

Northwest Coastal.

New storm snow will be touchy on Saturday and lingering persistent weak layers are still a concern. Conservative terrain use is critical.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

FRIDAY NIGHT: Flurries with 10 cm of new snow and 30-50 km/h southeast winds.SATURDAY: Scattered flurries with 5-10 cm of new snow, 30-50 km/h southeast winds, alpine temperatures around -15.SUNDAY: Cloudy, moderate east winds, alpine temperatures around -12.MONDAY: Mix of sun and cloud, moderate to strong outflow (east) winds, alpine temperatures around -12.

Avalanche Summary

Another natural persistent slab avalanche was reported in the Ningunsaw area on Thursday, indicating that the persistent problem will linger for some time in the northern part of the region. No recent avalanches have been reported in the southern part of the region.On Saturday, the primary concern is fresh storm slabs with the new snow, although triggering deeper persistent layers remains possible.

Snowpack Summary

20-40 cm of new storm snow sits above a variable interface composed of hard wind slabs, weak surface hoar, and faceted snow. Expect the new snow to bond poorly to this interface and form extra touchy storm slabs on wind-loaded features. Below the new snow, a well settled slab sits above the Christmas surface hoar layer, which is now buried 40-80 cm deep and may still be reactive in sheltered areas. Deeper weak layers have only been reactive in areas with thin snowpacks. This includes a facet layer from early December that has been reactive in snowpack tests at lower elevations in the southern part of the region, and weak facets near the ground that have produced avalanches in the northern part of the region.

Problems

Storm Slabs

New storm snow sits above various weak layers and will be easy to trigger on Saturday. Expect extra thick and touchy storm slabs on wind-loaded features.

Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.Minimize exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

New snow has added load to our persistent weak layers. Take extra care to avoid thin trigger points and exposure to overhead hazard during the storm.

Use conservative route selection, stick to moderate angled terrain with low consequence.Be aware of the potential for large avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 7th, 2017 2:00PM