Avalanche Forecast

Issued: Jan 14th, 2016 8:00AM

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

chris gooliaff, Parks Canada

Glacier.

We are back into avalanche season. Touchy wind slabs are forming in the alpine and in exposed tree-line features.

Summary

Weather Forecast

We'll see isolated flurries today, with ridge top winds gusting to moderate from the west. Freezing levels remain below 800m. Friday will bring mixed sun/cloud with little in the way of precipitation. Winds remain light to moderate with freezing levels in the valley bottom. Light to moderate snowfall is forecasted for the weekend.

Snowpack Summary

In the alpine up to 35 cm of new snow buries the January 4th interface. This interface is surface hoar in protected areas, sun crust on steep S - SW aspects and loose facets at tree-line and below. Winds overnight have begun gusting to moderate values from the SW, creating a more reactive slab.

Avalanche Summary

Yes, we have something to talk about here! Numerous slab avalanches from N and S aspects (Mt Macdonald and Mt Tupper) were observed yesterday. Size ranged from 1.5 to 3.5, with steep, rocky start zones, and most avalanches running close to valley bottom. A few loose and slab avalanches to size 2 were observed west of Rogers Pass.

Confidence

Wind effect is extremely variable

Problems

Storm Slabs

25-35cm of new, low density snow is being moved around by the winds at ridge-top. This is forming a slab in lee features, which will likely have a poor bond to the underlying interface of surface hoar, sun crust, or facets.

Use caution in lee areas. Wind loading could create slabs.Use caution on open slopes and convex rolls

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Dry

Up to 35cm of new snow overlies the weak facetted Jan 4 layer. Expect this new snow to sluff in steep terrain and run fast. This is a concern around features like gullies or steep terrain where a fall could have consequences.

Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 15th, 2016 8:00AM