Avalanche Forecast

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Thursday: Dry with increasing high clouds throughout the day and moderate snowfall starting in the evening. Light winds increasing to strong southeasterlies with the onset of the storm. Freezing levels rising as high as 2000m, or higher in the south, but dropping in the evening. Friday: Heavy snow and strong southwesterly winds tapering off in the morning with 20-30cm total possible by midday. Freezing levels are expected to drop to 700m. Saturday: Continued moderate precipitation and strong winds with freezing levels remaining in the 500-700m range.

Tuesday's reports from Duffey Lake and Chilcotin areas suggest that a persistent facet/crust weakness is very touchy in treeline gullies and below treeline cutblocks. Several Size 2.0-2.5 persistent slabs, including multiple sympathetic releases, were skier-triggered in treeline features (gullies) and below treeline cutblocks. More reports of Mondays widespread avalanche cycle are coming in with loose snow and storm slab avalanches p to Size 3 observed on all aspects and at all elevations. In the Coquihalla area recent heavy loading from snow and wind resulted in several Size 3-4 natural avalanches. Two Size 4 slab avalanches were observed on northwest through east aspects. One was a 5-10m thick slab and took out large swaths of mature forest in the runout, while the other was a relatively thin slab at 1-2m but propagated approximately 1.5 Km across a bowl.

Strong and variable winds in exposed treeline and alpine areas has resulted in reverse loading, widespread surface crusts, and looming undermined cornices. In the Duffey Lake and Chilcotin regions south aspects are described as spooky with a very hollow feeling with a couple of different poorly-bonded crusts in the upper snowpack. The lower weakness, down 50-75cm at treeline is not only particularly touchy on south aspects, but on all aspects at lower treeline and below, where there is also an associated crust. Lingering pockets of this mid-February surface hoar and/or facets elsewhere (steep easterly aspects, sheltered concave slopes, and protected valleys, for instance) necessitates continued "heads-up" travel. Meanwhile in the Cascades, 70-100cm of recent storm snow combined with five straight days of sustained extreme winds has created a highly unstable wind and storm slab problem that will probably take a few days to settle and strengthen.