Watch for patterns of wind transport to avoid freshly formed wind slab hazards on Friday and keep giving cornices a wide berth.
Southwesterly winds continue to form wind slabs that may be reactive to human triggers on lee and cross-loaded terrain in the alpine. Keep your guard up on steep sheltered slopes where recent accumulations may overlie a weak layer of surface hoar on north aspects or a crust on solar aspects.
Thursday night: Cloudy with scattered flurries bringing about 5 cm of new snow. Strong southwest winds.
Friday: Cloudy with continuing scattered flurries and a trace to 5 cm of new snow. Moderate to strong southwest winds. Alpine high temperatures around -8.
Saturday: Cloudy with isolated flurries and a trace of new snow, increasing a bit overnight. Moderate to strong southwest winds, becoming extreme overnight. Alpine high temperatures around -9.
Sunday: Cloudy with continuing scattered flurries with another trace to 5 cm of new snow (up to 10 cm with overnight accumulations). Strong to extreme south winds easing to light southwest by evening.
No new natural avalanches were reported on Tuesday or Wednesday with limited field observations. That said, a guide on belay was able to trigger a large (size 2), touchy cornice chunk with a kick on Wednesday afternoon at 1650 metres in the Hudson Bay Mountain area. A few size 1 skier triggered wind slab avalanches in the alpine were reported on Monday.
A natural avalanche cycle with storm slab avalanches up to size 2.5 (large) were reported in the southwest of the region throughout the weekend.
Up to 5 cm per 12 hour period is expected to continue accumulating over the next couple of days. With elevated winds, the new snow may form fresh wind slabs on lee features below alpine ridgetops. It will otherwise add to 20-30 cm of storm snow from over the weekend. Storm totals in the southwest of the region are closer to 50-100 cm. At lower elevations, recent precipitation fell as rain, creating crusty surfaces.
Collectively, our new and recent snow overlies a variety of surfaces, including hard wind affected snow at alpine elevations, weak surface hoar crystals on northerly aspects and in sheltered terrain features around treeline, or a melt-freeze crust on southerly aspects and below treeline.
The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and always have the potential of being triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.
