Storm slabs may be reactive to skier and rider triggering, especially in the Telkwa area where heavier snowfall amounts exist. They could be extra sensitive on wind-loaded slopes
The spring sun packs a punch and can quickly initiate natural avalanche activity and weaken cornices
Cornices are large and looming along many ridgelines, and have likely grown with the recent snow and wind. They require a large berth from above and below. Direct sun and rising freezing levels can weaken cornices significantly.
Fresh and reactive storm slabs are likely to be encountered, especially in wind-loaded areas at upper elevations. A change in wind direction means that wind loading may be found on many aspects.
Keep in mind that brief periods of sun can initiate natural avalanches, especially in areas that saw high snowfall amounts.
Yet another Pacific frontal system hits the region Tuesday night bringing strong wind and new storm snow. Forecast snow amounts will vary across the region.
Wednesday: Mix of sun and cloud with snow amounts 5-10 cm. Ridgetop wind strong from the South. Alpine temperatures near -6 and freezing levels 1000 m.
Thursday: Mix of sun and cloud with light snow up to 10 cm. Ridgetop wind strong from the southwest and freezing levels 800 m.
Friday: Continued flurries 5-10 cm. Ridgetop wind strong from the southeast with freezing levels 1200 m.
On Monday, reports from the Telkwa area saw a widespread avalanche cycle that occurred over the weekend. This included loose dry avalanches at all elevations up to size 2 and wind slabs up to size 2.5. With the Telkwa receiving the most snow throughout the region this zone and the ranges to the West are likely a hot spot for avalanche activity in the upper snowpack and may take longer to stabilize and bond.
Avalanche size and sensitivity are expected to decrease over the next few days, however, reactive storm slabs are still anticipated, especially in wind-loaded slopes at upper elevations. If the sun comes out, it could quickly trigger natural avalanches within the new snow.
Cornices are large at this time of year, and they become weaker when the sun hits them.
15-35 cm of snow has fallen in the region over the weekend and another 20 cm fell in the Telkwa overnight. This was accompanied by strong southwest to northwest wind. Fresh wind slabs may exist on most slopes due to changing wind directions. At lower elevations, much of this precipitation fell as rain below treeline. The lower elevations are now showing a firm surface crust.
Buried 70-120 cm deep, a spotty layer of surface hoar may exist on sheltered north aspects, as well as a crust on south aspects and below 1450 m. Recent observations suggest that this interface is bonding.
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 have the potential to be triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.
