Cautious route-finding will be important at upper elevations as fresh wind slabs are possible to trigger.
Wind slabs can be expected in lee terrain features in the alpine and treeline, formed by recent snowfall and westerly winds. These wind slabs will be most reactive where they overlie a slick crust.
Springtime cornices are large, weak and unpredictable. Give them a wide berth when traveling at ridge crest and avoid overhead exposure.
Rain and rising freezing levels will weaken the upper snowpack. Wet loose activity can be expected on lower elevations. Watch for wet and heavy snow conditions.
Even brief periods of sunshine may pack enough punch to trigger surface snow on southerly aspects.
Friday: Mostly overcast skies with 5-10 cm of new snow. Ridgetop wind will be moderate from the West. Freezing levels will likely rise to 1500 m during the day and fall to the valley bottom overnight.
Saturday/ Sunday: Mix of sun and cloud with isolated flurries. Ridgetop wind is moderate from the southwest and freezing levels will remain 1500 m.
On Wednesday in the Renshaw area, several natural wind slab avalanches were reported and machine-triggered slabs up to size 1.
Several small (size 1) wet loose avalanches were observed in the Kakwa on Tuesday out of steep terrain as a result of warm temperatures and strong solar radiation.
On Monday, a size 1.5 skier-triggered wind slab occurred on south aspect at treeline. This wind slab failed on a slick crust below the new snow.
10-20 cm of new snow overlies 20 cm of denser snow that tapers rapidly with elevation. Westerly winds have formed wind slabs in the alpine and exposed treeline. A crust or moist snow can be found below the new snow on all aspects as high as 2000 m and to the mountain top on solar aspects. Below the crust, the top 10-30 cm of the snowpack is moist.
There are no deeper concerns at this time.
