Watch for active wind transport building fresh and reactive slabs on south facing slopes.
Sheltered areas should hold great riding conditions, seek them out and be aware of overhead hazard.
Wind slabs may be found near ridgelines or lower on the slope than usual. Watch for crossloading in unusual features like mid slope gullies and rollovers.
Naturally triggered wind slabs were reported on Friday, in wind affected features at higher elevations. We expect reactivity to continue.
Activity on the buried weak layers was last reported on Wednesday, with a size 2.5 on a reloaded (weaker) bed surface in a northwest facing slope in the alpine. Last Saturday, a very large avalanche was reported on Joffre shoulder. Persistent avalanches are still possible in shallow snowpack areas, or from step down avalanches.
Wind slab exists on south facing slopes at treeline and above, from northerly winds. Slabs may overly wind affected surfaces or surface hoar in sheltered areas.
A crust is found at treeline and below, 40-80 cm down. In some areas, a layer of surface hoar exists above the crust.
Another weak layer of facets or surface hoar overlying a crust is found at the base of the snowpack down 80 to 120 cm. This is the suspected failure plane for large avalanches in the region that occurred on January 6th and 10th. While the reactivity appears to be decreasing, triggering is most likely at high elevations where the snowpack is shallow.
Snowpack depths are 100 to 140 cm at treeline and decrease rapidly below.
Saturday Night
Clear skies with northerly winds increasing 15-50 km/h. Treeline temperatures rise to -18 °C.
Sunday
Sunny with northerly winds 20-50 km/h. Treeline temperatures around -17 °C.
Monday
Sunny with northerly winds easing 10-20 km/h. Treeline temperatures rise to -13 °C.
Tuesday
Sunny with southwest winds winds strengthening, 15-50 km/h. Treeline temperatures rise to -11 °C.
More details can be found in the Mountain Weather Forecast.
