Avalanche Forecast

Fair

The warm, moist storm system will continue to produce precipitation on Thursday night and Friday morning. An Arctic high pressure system will move into the region sometime during the day on Friday. Temperatures are expected to drop substantially on Saturday and persist for a few days.Thurs. night/Fri. morning: Precipitation 10-20mm, freezing level around 2000m, strong SW alpine wind. Friday afternoon: Precipitation tapering off, freezing level falling to valley bottom, alpine winds easing. Saturday: A mix of sun and cloud, light flurries possible, treeline temperature around -15C, calm to light N alpine wind.Sunday: Mostly sunny, treeline temperature around -20C, light N alpine wind.

On Thursday, Glacier National Park reported widespread natural avalanches up to size 3.5. Observations in the S. Columbia region are still very limited but it is expected that similar avalanche activity is occurring throughout the region.

The storm produced a slab up to 1m thick which sits on the mid-November weak layer (facets, surface hoar, and/or a sun crust on steep southerly slopes). 20-30cm below this layer is a thick rain crust with weak facets on top. In the Rogers Pass area, the storm slab is poorly bonded to the mid-November layer and snowpack tests suggest it can be triggered easily with wide propagations possible. In some tests, the deeper crust/facet layer was also failing and it is possible that avalanches may step down to this lower layer. Recent strong and variable winds have created wind slabs in exposed terrain and resulted in variable snow distribution in the alpine. At lower elevations expect travel to be difficult and potentially hazardous as many early season hazards are exposed or lightly buried (stumps, logs, rocks, open creeks, etc).