Avalanche Forecast

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

Thursday night: Moderate precipitation. Strong to extreme S winds. Freezing level around 1500-1800 m.Friday: Steady, moderate to heavy precipitation. Strong to extreme SW winds. Freezing level around 1800 m.Saturday: Light to moderate precipitation. Winds easing to moderate southerly. Freezing level around1800 m, lowering to  around 1000 m.Sunday: Lingering snow showers could bring up to 15 cm snow. It may clear up. Light winds. Freezing level around 800 m.

Almost every day this week, skiers have triggered slabs to size 2, failing on buried surface hoar/crusts which exist at all elevations and on all aspects. Some were triggered remotely, and they exhibited wide propagation. Details of some of these incidents can be found here. A natural cycle to size 2.5 occurred on Sunday night and Monday in response to new snow and wind-loading. A natural avalanche cycle is expected over the next few days in response to intense storm loading.

Two very touchy weaknesses of surface hoar and/or a crust within the upper metre or so of the snowpack have already been responsible for a number of avalanche incidents. Add an intense storm, with heavy precipitation rates, warming and very strong winds, and we have a good recipe for widespread avalanche activity. The lower snowpack is well settled.