Strong winds and up to 20cm of snow on Wednesday may push the alpine danger to HIGH.
Stick to conservative terrain and avoid overhead hazard as the snowpack adjusts to all the recent snow
Continued inputs of snow combined with moderate to strong south to west winds have created fresh wind slabs in the alpine and in open terrain at treeline. Slab development will continue through Wednesday as this pattern of incremental loading persists.
10-20cm of new snow and strong winds forecasted on Wednesday will sluff easily in steep terrain.
We are transitioning this problem from a PS to a DPS given the depth and behavior of recent avalanches. These avalanches are failing on either a nov crust/ facet interface near the ground or on the ground itself. Regardless of the failure plane, any avalanche triggered on this layer could be big!
Lake Louise ski patrol noted several small soft slabs in steep alpine terrain. These were from a surprise ~ 20 cm overnight and were generally small and predictably triggered.
Sunshine had similar small windslabs and reactive cornices with their control.
However, avalanche control at ski hills and along the 93N on Monday triggered several large avalanches including one that crossed the road at Mt. Hector.
10-20cm of snow over the last 48 hours brings the total snow depth over the December 15 melt-freeze crust (below ~2000m) up to 35-60cm. Moderate to strong S-W winds continue to develop slabs in the alpine and at treeline.
The mid-November facet/crust layers are down 80-140 cm and remain active this week with numerous large natural and explosive controlled avalanches.
Treeline snow depths are between 100-180 cm.
We are in a SW flow pattern with intermittent cold fronts sweeping through bringing flurries and winds.
Wednesday will be stormy, with 5-20 cm of snow and strong south winds.
Thursday should be drier with snow starting in the evening bringing another 5-15cm by Saturday with moderate to strong SW winds.
Link to updated weather forecast tables from Environment Canada
