Conditions will change rapidly as we enter the weekend. Watch for sluffing from steep terrain at all elevations and for signs of early wind slab development in the alpine.
Summary
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
The first wave of precipitation is expected to reach the interior late Thursday night or early Friday morning. 10-20cm of new snow is expected for Friday. Freezing levels are expected to be 1200-1500m and alpine winds moderate to strong from the SW. A weak ridge will keep Friday night and Saturday morning mainly dry before the next storm front arrives on Saturday afternoon or evening. Freezing levels on Saturday will rise to around 1500m or so and alpine winds will increase to strong from the SW. Saturday night and Sunday should yield another 20-40cm of snowfall up high. Freezing levels on Sunday may rise as high as 2000m and winds will remain strong.
Avalanche Summary
An early report on Thursday suggests the new snow is sluffing fast on the surface hoar/crust interface. With another 10-20cm expected overnight, these sluffs may be big enough by tomorrow to knock you off your feet. Caution to steep slopes and terrain traps.
Snowpack Summary
The new snow sits on a layer of large surface hoar. Up to around 2100m elevation this surface hoar sits on a hard rain crust. Above 2100m the surface hoar sits on well settled and faceted snow. As wind increases with the progression of the storm, wind slabs are expected to form in leeward features. A thick rain crust with facets from early November is buried over 1 m down and may still be reactive in isolated areas.
rbuhler,
Avalanche Canada
