Avalanche Forecast

Issued: Feb 10th, 2017 4:47PM

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

Avalanche Canada cgarritty, Avalanche Canada

A Special Public Avalanche Warning applies to this region. Don't lower your guard yet. Strong winds will do their part to maintain touchy conditions and elevated avalanche danger on Saturday.

Summary

Confidence

Moderate - Freezing levels are uncertain on Sunday

Weather Forecast

Friday night: Flurries bringing 5-10 cm of new snow. Winds strong to extreme from the southwest.Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Winds moderate to strong from the west. Freezing level reaching approximately 800 metres with alpine temperatures around -8.Sunday: Mainly cloudy. Winds moderate to strong from the southwest. Freezing level rising to approximately 1500 metres with alpine temperatures of -4.Monday: Cloudy with sunny periods. Winds light from the southwest. Freezing level to 2000 metres or potentially higher with alpine temperatures +1.

Avalanche Summary

Reports from the Fernie area indicate widespread natural, skier controlled, as well as remotely triggered avalanche activity to size 1.5. One Size 3 avalanche ran naturally in steep alpine terrain in the late afternoon on Thursday. Most avalanches have been isolated to the depth of 40cm in the most recent moist storm snow and activity has been noted at all elevations and on all aspects. Previously buried surface hoar, facets, and/or a sun crust may increase the reactivity and propagation propensity of storm slabs.

Snowpack Summary

Up to 35mm of precipitation fell over Thursday night, with periods of rain leading to diminished new snow amounts of around 15-25 cm at treeline elevations. This precipitation fell over the roughly 40cm of moist new snow from Thursday, adding additional load to the 60-80cm of storm snow that accumulated in the region last weekend. Strong shifting winds redistributed the previous storm's snow in exposed terrain forming touchy wind slabs. These wind slabs are now obscured by the latest round of snowfall. The combined accumulation of multiple storms' snow now overlies a highly variable old surface which included wind affected surfaces, a layer of surface hoar in sheltered areas, facets, and/or a thin sun crust. Recent reports suggest a poor bond between the new snow and the old surface. The mid and lower snowpack are generally well settled and stable but isolated basal weaknesses may exist in shallow snowpack areas.

Problems

Storm Slabs

An icon showing Storm Slabs
Additional new snow, warmer temperatures and strong winds have created touchy new storm and wind slabs.
Be cautious as you transition into wind affected terrain.Use conservative route selection, choose low angled and supported terrain with low consequence.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Feb 11th, 2017 2:00PM

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