Northerly winds have built reactive slabs in a reverse loading pattern. Expect wind slabs on south facing slopes near ridgelines and rollovers, and watch for crossloaded features.
Slabs are most prevalent at alpine elevations. Be aware wind loading may be found near ridgelines or lower on the slope than usual. Watch for crossloading in unusual features like mid slope gullies.
On Thursday wind slabs were triggered by riders, up to size 2 as northerly winds began to transport snow.
A machine remotely triggered an avalanche on a northeast facing slope at treeline on Tuesday. It's unknown what layer this avalanche failed on, likely within the recent storm snow or on the buried melt freeze crust.
Up to 50 cm of available snow is being redistributed into wind slabs on south facing slopes from these (northerly) arctic winds. Slabs may overly wind affected surfaces or surface hoar in sheltered areas.
A crust is found 60-80 cm deep and becomes thin and variable above 1900 m. Reports suggest this is beginning to break down.
Another crust from early Dec is 80-150 cm deep. A few large avalanches observed in the region on January 6 are suspected of failing on this layer. While reports suggest this layer is becoming less reactive, it is most likely triggered in high-elevation areas where the snowpack is thin and shallow.
Snowpack depths are 120-230 cm around treeline and decrease rapidly below.
Friday Night
Clear skies with northerly winds 10-30 km/h. Treeline temperatures remain around -25 °C.
Saturday
Sunny with northerly winds 15-30 km/h. Treeline temperatures reach -15 °C.
Sunday
Sunny with northerly winds 30-50 km/h. Treeline temperatures reach -10 °C.
Monday
Sunny with northerly winds 10-20 km/h. Treeline temperatures reach -10 °C.
More details can be found in the Mountain Weather Forecast.
