Avalanche Forecast

Poor - Timing of incoming weather is uncertain

Another frontal system will hit the Northwest tonight bringing moderate to heavy precipitation and strong winds through Wednesday afternoon. Tonight through Wednesday: 15-30cm (heaviest in the south). Very strong SW winds. Freezing level (FL) rising to around 1000m in the afternoon. Thursday: Mainly cloudy with a chance of flurries. Light to moderate SW-SE winds. FL near valley bottom. Friday: A mix of sun and cloud and much cooler. FL at valley bottom (valley temps of -10).

Observations from the Microwave area (S. of Dennis Lake) on Dec. 26: Several easily triggered soft slabs on steep features up to treeline. No alpine observations due to cranking winds and blowing snow. I would expect some natural avalanche activity at higher elevations, primarily in wind loaded terrain.

Strong winds have been the biggest storey recently. Exposed windward slopes have been scoured and wind slabs have formed in lee terrain and may be susceptible to human triggering. There is now around 55-70cms of snow sitting on a surface hoar/crust/facet combo which is the result of the early December dry spell. This crust is widespread and exists in most start zones up to 2000m. Facets can reportedly be found above or below the crust. Prior to being buried, the surface hoar was destroyed by high winds in the alpine, but still coexists with the crust at treeline and below. What is the tipping point of this weak interface? In areas where this interface has reached its threshold, natural and human triggered avalanches up to size 2.5 have occurred. If they have yet to happen, I suspect they are gaining some strength but would still react to a rider trigger, especially in steeper, unsupported terrain features. In short, the upper snowpack is variable and deserves caution. It will also see increased load with forecast wind and snow. Beneath this the midpack is well settled and strong.