Fading persistent slabs have made things easier to manage, but skiers and riders have been triggering surface slabs in wind-affected terrain. Sniff out the soft snow to keep it safe and fun.
Wind slabs may be reactive in leeward terrain at upper elevations and may slide especially easily where they overlie crust. Recent flurries and shifting winds may have obscured the problem and/or widened its distribution.
Soft wind slabs developing in the alpine produced releases to size 1.5 with sled traffic, to size 1 with skier traffic, and ran naturally to size 2 in the southeast of the region on Thursday.
There was a widespread natural avalanche cycle during the storm on the weekend. It produced several size 3 persistent slab avalanches suspected to have run on the February crust layer. These observations were focused at treeline elevation in the east of the region.
About 50 cm of snow since March 7 has been redistributed by strong winds in exposed alpine and treeline terrain. It sits on old wind effect at these elevations and on a melt-freeze crust to at least 1600 m. It may contain two crusts on treeline solar aspects and gave moderate, sudden test results on 60 cm-deep stellar grains in Allan Creek Thursday.
Layers from late Jan and early Feb, both made of surface hoar, facets, and/or crust, are 100 to 150 cm deep. They're showing up less in test results but may remain a problem in isolated thin-to-thick snowpack areas above the elevation of our newest crust. A north aspect at 1600 m in the lower Canoe gave moderate, propagating results on the 90 cm-deep Jan layer Wednesday.
Friday Night
Partly cloudy with isolated flurries and a trace of new snow. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -12 °C.
Saturday
A mix of sun and clouds with isolated flurries and a trace of new snow, mainly on the east slope. 30 km/h northwest ridgetop wind. Treeline temperature -13 °C.
Sunday
A mix of sun and cloud with cloud increasing and flurries bringing a few cm of new snow before increasing overnight. 30 to 50 km/h west ridgetop wind, shifting south and increasing. Treeline temperature -8 °C.
Monday
Cloudy with continuing snowfall bringing. 15 to 20 cm of new snow. 50 to 80 km/h southwest ridgetop wind, increasing. Treeline temperature reaching 1 °C as freezing level jumps to 2100 m.
More details can be found in the Mountain Weather Forecast.
