Avalanche Forecast

Moderate -

Someone or something is playing with the storm switch, flipping it back and forth. Storm on, storm off, storm on. We get a brief respite Monday which may even offer a bit of sun. Another storm approaches the coast moving through the interior on Tuesday/Wednesday.SUNDAY NIGHT: Freezing level at valley bottom, light west/southwest breeze at most elevations with strong west wind at ridgetop, trace of snow possible.MONDAY: Scattered cloud cover, freezing level at valley bottom, light southwest wind at most elevations, strong west/northwest wind at ridgetop, trace of snow possible.TUESDAY: Clear skies at dawn with cloud cover steadily increasing through the day, freezing level at valley bottom, light variable wind, no significant precipitation expected.WEDNESDAY: Broken cloud cover, freezing level at valley bottom, light variable wind at most elevations with moderate southwest wind at ridgetop, a few centimeters of snow possible.

Natural avalanche activity continued into Saturday on north and northeast facing alpine terrain between 2100 and 2700 m, producing avalanches to size 3. A skier triggered a size 2 avalanche on a steep east facing slope at 2400 m from 10 m away, the resulting avalanche had a crown 30 to 60 cm in depth. In a separate incident a skier triggered a small size 1 avalanche on a treed slope at 2050 m that faced northeast. Explosive control work on Saturday produced avalanches size 2 to 4 on all aspects (except for south) in alpine terrain between 2300 and 2700 m.Evidence of a widespread natural avalanche cycle was observed on Friday. Storm slabs were reactive to skier traffic and explosives, producing large (size 2 to 3) avalanches with depths around 40 cm. A couple avalanches were observed on the deeper layers described in the snowpack summary.

The recent storm dropped variable snowfall amounts across the region. In the north, upwards of 100 cm of snow fell. In the remainder of the region, around 40 to 60 cm of snow accumulated. The snow fell with strong westerly winds, so the deepest and touchiest deposits will likely be in lee terrain features. The freezing level rose to around 1500 m on Friday, so expect to find wet snow or a frozen crust below this elevation.All this snow is loading a weak layer that formed during the dry spell in early December. It is around 80 to 120 cm deep. The layer is composed of weak and sugary faceted snow, feathery surface hoar crystals, and on south aspects also a sun crust. The base of the snowpack is composed of weak faceted snow at alpine and treeline elevations. These basal weak layers have been producing large avalanches as recently as December 31. Human triggering any of these layers is most likely on slopes that didn't previously avalanche and on slopes that have variable snowpack depth, such as rocky alpine features.