Summary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Warm air enters the region late Sunday persisting through mid-day Monday. Freezing levels are forecast to be between 1500 - 2000 m & winds in the alpine will be ripping out of SW @ 55 -95 k/hr A cold front moves in after lunch Monday lowering freezing levels and bringing light snowfall, 5 cm or so are expected Monday night. A weak ridge builds in Tuesday AM before a more organized low moves in Tuesday afternoon into Wednesday. We can expect 15 - 20 cm before the system exits to the east Wednesday afternoon.
Avalanche Summary
Many small natural avalanches confined to the new snow have been reported from the region. While important to note, the bigger story is the continued activity on the mid-December surface hoar/facet/crust layer. Remote triggering (setting off avalanches from afar) continues to be reported. The bottom line is that this layer is still sensitive to the weight of a skier or sledder. It's also significant that avalanches failing on this layer are being reported in areas users often consider safe, such as moderately angled slopes near treeline. Large loads produced avalanches to size 3 (big enough to bury/destroy a car) in the region Saturday.
Snowpack Summary
80 - 120cm of total storm snow has fallen in the region since Christmas. Winds have redistributed the storm snow into wind slabs that are quite widespread; you can find them at and above treeline in wind exposed locations. Even open areas below treeline are suspect for wind affected snow. A surface hoar/facet/crust interface (persistent weakness aka PWL) from mid-December is buried anywhere from 80-120cm deep & has been quite reactive making for touchy avalanche conditions.
ghelgeson,
Avalanche Canada
