Avalanche Forecast

Good

Synopsis: A frontal system will cross the South Coast tonight bringing heavy precipitation, strong to extreme winds, and rising freezing levels. Drier but unsettled conditions are expected in the wake of the system on Thursday and into Friday. Tonight and Wednesday: Heavy snow – 30-40 cm. The freezing level will climb as high as 1500 m before dropping sharply in the evening. Winds are strong to extreme from the southwest. Thursday: Mainly cloudy with a chance of flurries. The freezing level drops to around 500 m and winds ease to moderate from the west-southwest. Friday: A mix of sun and cloud with a slight chance of flurries. Temperatures remain cool with the freezing level around 600 m.

On Tuesday morning there was a report of a size 2.5 skier triggered avalanche in the Blackcomb backcountry. The slide occurred on a southeast aspect in the alpine and the crown was approximately 100 cm deep. This event resulted in 2 full burials and 2 partial burials. One group triggered the avalanche which ran into another group below. Fortunately everyone involved was rescued successfully. There have been a few other reports of rider triggered avalanches up to size 2 in the past couple days. Most have been from northerly aspect in the alpine or at treeline. There was also a report of a size 3 cornice triggered avalanche on Monday, highlighting the potential for large avalanches.

20-30 cm new snow now sits on a weak crust below 1900 m. Below the crust is moist snow, from the previous intense, wet storm. Freeze-up following this storm was slow, due to a slow decline in temperatures and the insulating skiff of snow on the surface. Below the recent new snow lies one or two weak layers buried approximately 60 cm below the surface. These comprise faceted snow, surface hoar and/or a crust. The snowpack structure is quite variable at this time. It may change dramatically with only a subtle change in elevation, aspect, wind or sun exposure. With further cooling, the upper snowpack should start to bond better. However, with the amount of moisture and the insulating effect of the new snow, expect this to take longer than usual. Mid and lower snowpack layers are well bonded.