Avalanche Forecast

Fair - Wind effect is extremely variable

Synopsis: An off shore Rex Block keeps the province under cold, dry northerly flow for the forecast period. But the models are starting to agree on a solution that shows the blocking pattern breaking down giving way to a steady flow of Pacific Storms early next week. Time will tell if this is all conjecture and hope, or something a bit more substantive.Thursday: Sky: Clear; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, EFriday: Sky: Clear; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, SWSaturday: Sky: Clear; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, NE

On Tuesday wind slabs averaging 20 cm in depth produced avalanches to size 2 that were sensitive to both natural and human triggering. These slabs were predominately on N through NW facing slopes.Deep Persistent Slabs have been removed from the problem portion of the forecast because it's probably a 1:1000 slope event at this time, but they haven't totally gone away. Two large natural avalanches (size3) were observed on a steep south facing alpine feature south of Revelstoke on Saturday.

Snow totals from the last pulse on Wednesday (140129) range from 5 - 20 cm with the greatest accumulations in the south of the region. This snow is faceting quickly in the cold temps. In wind exposed terrain, especially in the alpine, winds continue to form shallow wind slabs that are most prevalent immediately lee of ridgecrest. These variable wind slabs should stick around a bit longer than we're accustomed to as they are resting on a weak layer composed of large grained surface hoar (widespread in most sheltered and shaded areas at all elevations), a sun crust on open south facing slopes, faceted grains (in colder areas or areas with a thinner snowpack), or a combination of the above.Most of the snowpack is generally well consolidated. However, in thinner snowpack areas a facet/crust weakness may exist near the bottom of the snowpack. The depth of this layer makes human triggering unlikely, but the consequences of doing so could be disastrous.