The storm may have tapered-off, but persistent weaknesses have to the potential to surprise with nasty consequences. Conservative terrain selection remains critical.
Summary
Confidence
Fair - Due to the number of field observations
Weather Forecast
Generally light snowfall, strong southwest winds and freezing levels at 600m are expected on Wednesday. Snowfall is expected to intensify Wednesday evening and continue throughout Thursday. By Friday morning, we can expect up to 15cm of accumulated snowfall. Winds are forecast to remain strong and southwesterly during the system, and then become light and northwesterly as the snowfall tapers-off on Friday. Freezing levels should hover around 800m for Thursday and Friday.
Avalanche Summary
A few close calls on Sunday suggest that the region has undergone a fairly active avalanche pattern. In the Hankin area, a skier accidentally triggered a size 2.5 avalanche which resulted in a full burial and minor injuries. The avalanche was reported to have occurred on a wind-loaded, north-facing slope. The avalanche initially failed on the January crust/surface hoar combo, and then stepped-down to the November crust and basal facets. Thanks to the party involved for sharing this information, and good work on a quick and effective companion rescue.On the same day in the Sinclair area, a snowmobile may have been the trigger for a size 3 avalanche. The avalanche had a crown between 1 and 2 metres, and propagated up to 200 metres wide. It occurred on a wind-loaded, north-facing alpine slope and may have failed on the November crust facet combo. Given the persistent nature of these weak layers, there is ongoing potential to trigger these deeper, destructive layers.
Snowpack Summary
Moderate to heavy snowfall (with rain at lower elevations) and strong southwest winds have built deep and dense storm slabs. These storm slabs are expected to be most reactive in wind-exposed, upper elevation terrain. A rain crust and/or surface hoar layer buried mid-January may be found between 60- 100cm below the surface. This persistent weakness has been reactive with recent storm loading. Near the base of the snowpack is the crust-facet combination buried in November. This deep persistent weakness seems to have "woken-up" in some terrain in response to warming and heavy loading from wind and snow.
jlammers,
Avalanche Canada
