Avalanche Forecast

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Flurries are forecast to continue overnight and Monday resulting in another 5-8 cm of new snow above 500 metres elevation. Moderate southwest winds should continue until Monday afternoon, when the winds will switch to the northwest ahead of the next major system moving in from the Gulf of Alaska. There is a chance of some broken skies in the east of the region on Monday afternoon. Cloud, precipitation and strong southerly winds should start on Tuesday. At this time the models are not showing heavy precipitation moving inland, I suspect this may change as the system moves onto the coast. Expect at least 5-10 cm by Wednesday morning, and another 5-10 during the day. Stay tuned for updates as the storm approaches.

No new reports from Saturday or Sunday. Skiers in the Shames area reported natural and skier accidental avalanche activity up to size 1.5, and skier controlled up to size 2.0 on Friday. These avalanches are suspected to have released on a buried layer of decomposing surface hoar that is sitting on a firm supportive crust down about 50 cm in the alpine. There is only 10-15 cm of snow at 700 metres elevation, that quickly becomes a metre on the ground by 1000 metres elevation. This persistent weak layer is expected to continue to be reactive for the duration of this forecast. Other areas like Sterling, Wesach/ South Douglas are expected to have the same problem with buried surface hoar. Please submit your observations to the Mountain Information Network.

Recent snowpack information has been limited to reports from the Shames backcountry. Some earlier information came from Wesach that suggested the buried surface hoar problem exists there as well. The surface hoar in the Shames area was buried in mid-November and is now down about 30-60 cm and is sitting on a firm supportive crust. This weak layer has been reactive to light loads like individual skiers and riders. Shaded slopes in the alpine are the most likely spots to encounter this problem. Steep roll-overs and convex slopes tend to be more reactive to persistent weak layers like buried surface hoar. Areas that have released naturally or from skier traffic may be the safest spots after the next storm moves in early next week. Terrain that has not released may continue to be a problem for the duration of the forecast period. There is very little snow in the north of the region at Ningunsaw and Cassiar. Snow that is on the ground in these areas may be facetting and developing a weak basal layer.