A few wind triggered avalanches occurred on Wednesday. The basal snowpack layer remains weak and untrustworthy. Conservative route choices are still advised.
Strong SW winds on Wednesday created some new reactive windslabs in alpine and exposed treeline terrain. Winds diminish Thursday and the incoming flurries may hide existing windslabs.
Surface windslab avalanches have the potential to step down to the basal facets resulting in larger full depth avalanches. Given the weak snowpack structure, avalanches in motion have the potential to run further than expected into below treeline terrain.
A few wind triggered avalanches up to size 2 were observed Wednesday above Pilsner Pillar ice climb and in extreme terrain in Chickadee Valley. There have been more reports with the good visibility of avalanches up to size 2.5 that occurred after last weeks storm. Most originated in the alpine but some originated in treeline locations. On Saturday a size 2 skier triggered avalanche failed as a deep persistent slab at treeline and ran 600m scrubbing to ground.
Wind affect in the alpine from Wednesdays strong SW winds. At treeline, last week's storm snow has settled to 20-40cm over the Dec 2 weak layer which consists of the basal facets and surface hoar. A rain crust (1 to 7cm thick) exists within the storm snow up to 2300m on all aspects. The thickness of the rain crust tapers with increasing elevation and is more prevalent in the southern part of the region. Click here for snow profile done on Tuesday in the Dolomite peak area.
Winds decrease to moderate Wednesday night as flurries move into the region Thursday bringing 5-10 cm. Snow ends Thursday night and winds again pick up to strong on Friday. At treeline, the overnight lows will be around -10C with daytime highs around -5C for the next couple of days.
For more information, click Mountain Weather Forecast.
