Avalanche Forecast

Moderate - Timing, track, or intensity of incoming weather system is uncertain

TONIGHT: Cloudy. Ridge wind strong, west. Temperature -10. Freezing level valley bottom.SUNDAY: Cloudy, flurries. Accumulation 4-8 cm. Ridge wind light, southwest. Temperature -4. Freezing level valley bottom. MONDAY: Cloudy, flurries. Accumulation 2-8 cm. Ridge wind strong, southwest. Temperature near 0. Freezing level rising to 2000 m.TUESDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind strong, west. Temperature near 0. Freezing level lowering to 800 m.

Several large and very large avalanches have occurred on weak layers buried deep in the snowpack in recent days (including natural activity up to Size 3), highlighting that dangerous avalanche conditions exist within the region.Explosive control work on Friday and Saturday produced numerous storm slab avalanches Size 2-2.5, as well as several large, destructive Size 3-4, slab avalanches that failed on the mid-December and late-November layers, with crowns from 150-250 cm deep.On Wednesday and Thursday, numerous natural, skier and explosive triggered storm slab avalanches up to Size 3 were reported with crowns from 20-80 cm deep, and propagations from 20 up to 150 m wide.On Tuesday a Size 2 was triggered from 50 m away by a snow machine on a northeast aspect at 2050 m. The crown was 120 cm deep and is suspected to have failed on the mid-December weak layer.Reports from Monday included seven deep persistent slabs that were released with small explosives in the alpine in the Fernie area. Sizes ranged from 2.5-3, crown depths averaged about 200 cm and all results indicated the deeply buried late-November crust as the failure plane.

About 60-90 cm of settled storm snow now covers a layer of surface hoar on sheltered aspects (especially prominent from 1400-1900 m) and sun crust on solar aspects, that was buried mid-January. Beneath the mid-January interface lie a number of very concerning buried weak layers. A layer of surface hoar from early-January is buried 90-110 cm below the surface. A weak layer buried mid-December (predominantly surface hoar and/or a sun crust) is around 120-160 cm below the surface at treeline and below treeline elevations. A rain crust with sugary facets buried late-November is near the bottom of the snowpack and is now up to 200-250 cm below the surface. All of these layers remain active and have produced recent large, destructive avalanches.