A new Pacific storm system will start to brush up against the Northwest coast overnight. Avalanche danger will trend to HIGH by the weekend.
Summary
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A new Pacific storm system will start to brush up against the Northwest coast overnight. This series of low pressure systems will be deflected to the North by a strong ridge of High pressure over most of the province. Precipitation amounts are expected to be heaviest along the coast and near Kitimat and Stewart. Overnight: 5-10 cm, moderate southwest winds, freezing level 600 metres. Thursday: 10-25 cm with strong southwest winds, freezing level rising to 1000 metres. Friday: 20-40 cm with extreme southwest winds, freezing level rising to 1300 metres. Saturday: 25-50 cm with extreme southwest winds, freezing level rising to 1500 metres.
Avalanche Summary
One report on Wednesday of a skier triggered wind slab size 1.0 on a convex roll at 1500 metres that was about 25cm deep. Expect avalanche size and frequency to increase as the forecast storm moves into the region.
Snowpack Summary
There is 5-10 cm of new snow above the latest buried surface hoar layer from January 23rd that has been found up to size 10 mm at treeline and below. This surface hoar layer may be associated with a crust below 1100 metres. There continues to be several other surface hoar layers of concern from early January and Christmas. Some reports show these persistent weak layers to be rounding and bonding, however we are still getting some reports of sudden planar releases in snowpack tests with hard forces applied. I suspect the forecast heavy precipitation over the next few days will be a good test for these older buried weak layers.
triley,
Avalanche Canada
