See forecaster blog for a discussion on changing avalanche conditions.
Summary
Confidence
Fair - Intensity of incoming weather is uncertain on Saturday
Weather Forecast
By the end of Saturday, high snowfall areas in the region could see as much as 20 cm of low density new snow as a frontal system tracks along the US/Canadian border. Moderate southwest winds are expected and alpine temperatures should hover between -5 and -10C. For Sunday and Monday, a series of weak disturbances embedded in a northwesterly flow will bring light precipitation. Winds should be generally light or moderate, with the switch from southwesterly to northwesterly expected to occur on Sunday night.
Avalanche Summary
Wind slab pockets could be triggered on convex rolls on Friday at higher elevations. Two size 2 human-triggered avalanches were been reported from Kootenay Pass on Wednesday/Thursday, initiating on a surface hoar layer down around 15 cm on north east facing slopes below treeline. Things are changing. Check out the forecaster blog for a discussion on scenarios that may play out as the current situation evolves.
Snowpack Summary
Another 5-10cm of snow on Thursday has brought the total to about 15-25 cm of dry snow above the major surface hoar created at the beginning of the month. Some thin windslab may have developed in the alpine due to moderate westerly winds. This interface will be one to watch as it receives more snow load and/or the slab settles. Below that 30cm of near-surface facets can be found on shady slopes while a sun crust can be found on southerly aspects. In shallow snowpack areas concerns remain for the mid-December persistent weakness down around 80-100cm and for basal facets.
jfloyer,
Avalanche Canada
