North Columbia

Expect especially touchy storm slabs in the southern parts of the region where more new snow has accumulated and more is forecasted. Check out the South Columbia forecast for more details.

Moderate - Forecast snowfall amounts are uncertain on Thursday

THURSDAY: Mainly cloudy with 15-25 cm of fresh snow, moderate to strong southerly winds, and freezing level near valley bottoms.FRIDAY: Cloudy with flurries bringing another 5-10 cm of fresh snow, moderate to strong southwesterly winds, and freezing level remaining at valley bottoms.SATURDAY: Cloudy with flurries bringing another 5-10 cm of fresh snow, moderate to strong westerly winds, and freezing levels below valley bottoms.

Reports of natural and human triggered storm slab avalanches up to Size 2 continues, with some slabs exhibiting wider propagation than seen in previous days. Storm slabs are expected to remain sensitive to light triggers, especially where winds have promoted slab formation. Heavy loading from snow and wind could result in continued natural avalanche activity.

Most of the region received around 25-40cm of new, low-density snow over the past few days, while the northern tip of the region got much less. This recent storm snow has settled into a slab, especially where it has been wind-loaded or warmed by the sun, which is bonding poorly to the previous snow surface that includes sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. Recent reports identify buried sun crust as a particular problem. Weaknesses are also lingering within the recent storm snow, with several easy to moderate shears being reported in areas with higher amounts of recent storm snow. A persistent weakness buried mid January is now down 50-80 cm and consists of buried surface hoar in sheltered areas, and/or widespread faceted old snow. It has generally stabilized but may be sensitive to triggering in isolated areas where buried surface hoar is preserved. Another surface hoar/facet persistent weakness that was buried mid-December can now be found down roughly 110-130 cm. While activity at this layer has declined, professionals in the north of the region are still treating it with caution.