North Columbia

A Special Public Avalanche Warning (SPAW) is in effect for this region. Warming temperatures and strong winds are expected to give way to a natural avalanche cycle. Seek out low angle terrain free of overhead hazard.

Moderate - Freezing levels are uncertain

THURSDAY NIGHT - Flurries, 5-15 cm / south to southwest winds, 30-55 km/h / freezing level 1100m / alpine low temperature near -5FRIDAY - Mainly cloudy with flurries , up to 10 cm / south to southeast winds, 40-80 km/h / freezing level 1400-1700m / alpine high temperature near -2SATURDAY - A mix of sun and cloud with isolated flurries / south to southwest winds, 20-45 km/h / freezing level 900m / alpine high temperature near -8, low temperature near -12SUNDAY - Cloudy with sunny periods and isolated flurries / south to southeast winds, 20-45 km/h / freezing level 1200m / alpine high temperature near -2, low temperature near -9

Numerous avalanches up to size 3 were reported in the North Columbia region on Wednesday. The storm slab has been very reactive, producing both natural and human triggered avalanches. Several of these avalanches were triggered from a distance (remote triggered).

70-110 cm of recent storm snow sits on a weak layer that consists of facets (sugary snow), surface hoar (feathery crystals) and a sun crust on south aspects. The storm came in with moderate to strong winds that continue to persists throughout the region, creating widespread slab formation. A weak layer from mid November is now buried up to 150 cm and consists of surface hoar in shady locations, and a sun crust on steep south facing slopes. While not recently reactive, the potential may exist for storm slab avalanches to step down and trigger this deeper layer, resulting in large avalanches. The most likely place for this layer to be a problem is on steep, south facing slopes at treeline where the surface hoar sits on the sun crust.At the base of the snowpack is a crust that formed in late October. Concern for this layer is dwindling but it may still be worth considering in places such as steep, rocky, alpine terrain, especially where the snowpack is shallow. It would likely take a large trigger such as a cornice fall to produce an avalanche on this layer.