Choose terrain that is sheltered from the wind for the best riding and the lowest avalanche danger. In the last few days, riders have triggered wind slab avalanches below ridgecrests, and in crossloaded gullies.
Recent snow and moderate winds have built new wind slabs over older wind slabs. Expect these slabs to be most reactive in leeward terrain like ridgetops and cross-loaded features, and where a firm bed surface exists.
On Friday, a large (size 2), rider triggered, windslab avalanche was reported south of Crowsnest Pass. It occured in an open, cross-loaded feature below tree line on a north facing slope.
On Saturday, in neighboring Waterton National park, a similar but smaller (size 1.5) rider triggered avalanche occured on a southeast facing slope below treeline.
Wind slabs may linger directly lee of ridges at high elevations. See this MIN post for an example.
Please continue to share any observations or photos on the Mountain Information Network.
5 to 10 cm of recent snow coupled with moderate to strong southwest winds has built wind slabs in lee and crossloaded features at alpine and treeline elevations, and in open features below treeline. A melt-freeze crust can be found at 2100 m and below at variable depths, on the surface on windward slopes, and buried 15 to 20 cm in lees. Wind slabs may be more reactive where they sit on this crust.
The middle of the snowpack is consolidated. Weak faceted grains exist near the base of the snowpack.
The average snowpack depth is 120 cm. Up to 200 cm can be found in wind-loaded areas.
Monday Night
Cloudy. Possible trace of snow expected. Moderate to strong northwest ridgetop wind. Treeline temperatures -3 °C, freezing level 1700 m.
Tuesday
Cloudy. 1-2 cm of snow expected. Strong southwest ridgetop wind. Treeline temperatures -5 °C, freezing level 1700 m.
Wednesday
Mostly cloudy. 10-15 cm of snow expected overnight, possibly more in the south end of the region through the day, depending on the track of the storm. Moderate northwest or west ridgetop wind. Treeline temperatures around -9 °C.
Thursday
Mostly sunny. No new snow expected. Strong west or southwest ridgetop wind. Treeline temperatures increasing through the day to -2 °C.
More details can be found in the Mountain Weather Forecast.
