South Columbia

Difficult and dangerous conditions exist in the backcountry at this time. Choose cautious and conservative routes.

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Synopsis: Starting Thursday night, a Pineapple Express with a narrow moisture stream has the potential to bring moisture to part or all of this region through the forecast period. Due to the narrow moisture stream, there is poor confidence in snowfall amounts at this time.Thursday: Mostly dry during the day. Freezing level around 1200 m. Winds southwest, mostly light, increasing to strong on Thursday afternoonThursday night. 10-15 cm new snow, with the possibility of local enhancement. Very strong SW winds.Friday: Moderate snow/rain (around 10 cm/mm, but heavier amounts possible). Freezing level around 1800 m. Southwesterly ridgetop winds to 80 km/h.Saturday: Heavy snow/rain (around 20 cm/mm). Freezing level around 1900 m. Southerly winds around 30 km/h.

Two large avalanches (size 2 or 3) were remotely triggered from a flat ridge in the Monashees, one on Wednesday and one on Tuesday, both with a fracture depth of 130 cm. In both cases, there was steep north facing terrain directly below the ridge. On Tuesday, there were a good number of natural and human-triggered avalanches on all aspects reported up to size 3, mostly running on the February 12th surface hoar. Natural activity appeared to be triggered either by wind activity (mostly north and east aspects) or during periods of solar activity (southern aspects). Human triggered avalanches were easy and in some cases, surprising.The number, size, and destructive potential of recent avalanche events speak loudly to the touchy nature of the avalanche problem at this time.

Around a metre of storm snow now sits on a highly reactive weak layer of surface hoar layer which was buried on February 12th.The highly variable and destructive nature of this persistent weakness remains a primary concern for professionals in the region. This interface has also shown reactivity on southerly aspects where a sun crust also exists. The mid to lower snowpack layers are generally considered strong and well settled, but a significant period of loading and warming may have the potential to re-activate a more deeply buried layer within the snowpack. Recent and ongoing cornice growth with the current weather pattern is significant, and I expect them to be weak and potentially destructive with anticipated warm weather.