Northwest Coastal

Continued stormy weather will maintain elevated avalanche danger.

Good

Heavy snowfall or rain is expected to continue throughout the forecast period with 20-40 cm of snow (or mm of rain) each day for Friday, Saturday, and Sunday, although Friday is looking perhaps a little drier. Strong southwesterly winds are expected to ease off on Saturday and remain light to moderate on Sunday. Freezing levels around 1600 m on Friday are also expected to drop below 1500 m on Saturday, but fluctuate on Sunday.

Very heavy loading from snow, wind, and rain has resulted in a widespread natural avalanche cycle. Reports from Wednesday include numerous wind slab and some step-down persistent slab avalanches in the Size 2-3 range, with isolated deep persistent slab avalanches up to size 3.5 from large alpine features. Below approximately 1000m numerous wet loose snow avalanches up to Size 2.5 were observed running in steep terrain. This pattern should continue throughout the forecast period.

Heavy snowfall (with rain below  approximately 1500-1000 m) and strong southwest winds have built fresh deep and dense storm and wind slabs. The slabs are likely 'upside down' with warm temperatures dropping moist dense snow on previous dry lower-density snow. A  rain crust and/or surface hoar layer buried mid-December is down around a metre. Recent reports mention that this weakness has become 'electric' with recent heavy loading and has been responsible for much of the recent large avalanche activity. The November crust near the bottom of the snowpack is generally well bonded, but may 'wake up' with intense loading this week. There is potential for isolated very large and deep avalanches.