A week of steady snowfall and occasional strong winds has left large storm slabs and cornices primed for human triggering. Avoid overhead hazards and stick to mellow terrain.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're looking at occasional flurries and then a more organized system coming Thursday night. WEDNESDAY: Flurries overnight Tuesday with 5-10 cm of new snow, 20-30 km/h southwest winds, alpine temperatures around -7 C. THURSDAY: Cloudy with scattered flurries and up to 3-5 cm of new snow, 10-20 km/h southwest winds, alpine temperatures around -11 C. FRIDAY: Snow Thursday overnight into Friday (10-15cm) , 20-40 km/h southeast winds, alpine temperatures around -8 C.
Avalanche Summary
In the past two days at treeline and alpine, natural storm slab and loose dry avalanches to Size 2 have been reported on south through northeast aspects. Cornices are large and remain easy to trigger. A great image from Sunday illustrates just how surprising the results can be.
Click here for details. Several size 1.5 to 3 natural and explosives triggered avalanches were reported on Saturday. Aspects were east through northwest, from 1500m to ridgetop.Natural activity is expected to taper off, but storm slabs will remain likely for human triggering.
Snowpack Summary
Another day, another 10-20 cm of snow falling: The weekly total now stands at roughly 130 cm. At times, strong southwest winds have extensively redistributed the snow and formed large brittle cornices. Over the weekend the new snow came in "upside down" (heavier, denser snow over lighter snow) and is rapidly settling into a slab which sits over a variety of old surfaces including surface hoar, facets, stiff wind slabs, sun crusts, and a rain crust below 1900 m.Isolated basal weaknesses may still exist in shallow snowpack areas and appear to isolated to north-northeast aspects in the alpine.
mgrist,
Avalanche Canada
