Avalanche Forecast

Moderate -

Monday: A mix of sun and cloud. Light west winds. Alpine high temperatures of -11.Tuesday: Mainly cloudy with cloud increasing over the day. Flurries beginning in the evening Light west winds, increasing overnight. Alpine high temperatures of -10. Wednesday: Cloudy with continuing flurries bringing approximately 20 cm of new snow by the end of the day. Flurries continuing overnight. Light to moderate west winds. Alpine high temperatures around -4.

Reports from Saturday included observations of cornice-triggered storm slabs releasing from size 2-3.5 on southeast aspects. The size 3.5 avalanche showed wide propagation that extended the crown into low angle terrain. Two recent size 2-3 wind slab releases over the early January and mid-December weak layers were also observed. A size 2 persistent slab avalanche was also remote triggered by a snowmobiler approaching a short convex slope in the Allan Creek area. The crown fracture was over a metre deep. Explosive control on Thursday produced avalanches to size 2.5 failing on both the mid and early January interfaces. These avalanches ran on north, northeast, east and southeast facing features between 1600 and 2600 m. On Tuesday, a size 2.5 avalanche on a northeast facing slope at 1920 m resulted in a single fatality in Clemina Creek. More details available here.Looking forward, dangerous snowpack conditions will persist in the region. All three of our buried weak layers continue to produce large, destructive avalanches both naturally and with light triggers. The potential for new storm slabs and wind slabs to act as a trigger for deeper weak layers is another increasing concern.

Another round of snowfall began on Sunday morning and 10-15 cm of new snow is expected to accumulate on the surface by Monday. This is adding to 40-80 cm of recent storm snow that sits over an unstable snowpack with three active weak layers we are monitoring:1) The first layer is found beneath the recent storm snow and is formed of a crust and/or surface hoar layer that was buried in mid-January. The surface hoar is up to 10 mm in size, found at all elevation bands and has been very reactive on north through east aspects between 1900-2600 m. 2) Deeper in the snowpack, the early-January persistent weak layer is found 60 to 120 cm below the surface. This layer was reported as the most active persistent weak layer during a recent natural avalanche cycle that took place in the region. It was also very reactive to recent explosives control.3) Another weak layer buried mid-December consisting of a facet/surface hoar/crust combination is buried 110 to 160 cm deep. It has been most problematic at and below tree line. Many avalanches that failed at shallower weak layers 'stepped down' to this interface during the recent avalanche cycle and explosives control.