Avalanche Forecast

Issued: Mar 4th, 2017 5:04PM

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

Avalanche Canada cgarritty, Avalanche Canada

Resist the urge to step into bigger terrain this soon after the storm. The risk of triggering a storm slab will remain very real on Sunday.

Summary

Confidence

High -

Weather Forecast

Sunday: Cloudy with scattered flurries bringing approximately 5 cm of new snow. Light to moderate variable winds. Alpine temperatures of -7.Monday: Cloudy with flurries bringing 5-10 cm of new snow. Light to moderate southwest winds. Alpine temperatures of -9.Tuesday: Cloudy with flurries bringing approximately 10 cm of new snow. Moderate to strong south winds. Alpine temperatures of -8.

Avalanche Summary

Reports from Friday include several storm slab releases from Size 1-2.5, with the largest examples triggered naturally. All aspects shared fairly equal representation. Our mid-February interface proved quite reactive, yielding both ski cut and remotely triggered releases to Size 2, mainly at lower elevations where the crust is more prominent.Thursday's reports were similar, with more numerous storm slabs generally running a bit smaller at Size 1-1.5. The majority of these were triggered naturally and with ski cutting. Again, all aspects shared fairly equal representation, with natural and remote triggers more focused on north to east aspects.Looking forward, expect a decline in natural avalanche activity while the potential for human triggering to the depth of our new snow lingers for a few more days.

Snowpack Summary

Stormy weather since Tuesday night has delivered a wide-ranging 65-120 cm of new snow to the region, with the greatest accumulations initially occurring in the Monashees and more recently in the eastern Selkirks. Moderate to strong southerly winds have accompanied the new snow, promoting touchy wind slab formation in lee terrain at upper elevations. The new snow has buried widespread faceted surface snow as well as more isolated surface hoar to 4mm. A thin sun crust may exist below the new snow on steep solar aspects. About 90-135cm below the surface you'll find the mid-February interface which is composed of a thick rain crust up to about 1800 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. This layer has been producing inconsistent and broken results in snowpack tests but recent avalanche activity suggests it is still an active failure plane, especially over the crust at lower elevations. It may well develop into a persistent slab problem as the snow above it settles into a stiffer slab. The mid and lower snowpack are generally well settled and stable.

Problems

Storm Slabs

An icon showing Storm Slabs
Descriptions of very touchy conditions and natural avalanche cycles have dominated recent reports. As natural activity subsides, the potential for human triggering storm slabs lingers on. Expect the touchiest conditions in wind affected areas.
Be cautious as you transition into wind affected terrain.Be alert to conditions that change with elevation.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 5th, 2017 2:00PM

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