Avalanche Forecast

Moderate - Timing, track, or intensity of incoming weather system is uncertain

The last in a series of storm systems should bring heavy snowfall to the region overnight and Friday. 20-40cm of new snowfall is expected between Thursday night and Friday afternoon. Amounts are expected to be greatest along the coast and taper off inland. Alpine winds are expected to be strong from the south to southwest and freezing levels are forecast to hover around 1200m. Light snowfall is expected to continue Friday night and should taper off by Saturday morning when a ridge of pressure moves over the region. A mix of sun and cloud is expected for Saturday with light alpine winds and freezing levels around 1000m. Mostly sunny conditions are currently forecast for Sunday morning with a weak storm system arriving Sunday evening.

On Wednesday, no new natural avalanches were reported but isolated pockets of soft slab in leeward alpine features were reactive to skier triggering. Slabs were up to 30cm thick. Cornices were also reported to be touchy. On Tuesday, several ski cut and skier accidental avalanches were reported throughout the region. These were mostly storm slabs and wind slabs size 1-2. Most of the reported activity was on north through east aspects between 1800 and 2000m elevation. These slabs were typically 20-40cm thick and were failing within the recent storm snow. However, a couple storm slabs were also reported at 1600m and were failing on a rain crust. Storm slab avalanches are expected to be remain very reactive to human-triggering at higher elevations with ongoing snowfall and wind continuing into Friday. Natural avalanches are also possible and extra caution should be used in run out zones. Cornices are reported to large and fragile, and may fail under the weight of a person.

Another 15-30cm of snowfall Wednesday night brings the storm accumulation to 50-80cm over the past week. This snow overlies a thick rain crust which extends into the alpine. The snow is reported to be bonding well to the crust and all the recent avalanches have been failing within the recent storm snow, not on the crust interface. At treeline and below, other crusts may exist in the upper snowpack due to the recently fluctuating freezing levels. Freezing levels on Wednesday climbed to around 2000m and have to fallen to around 1600m on Thursday afternoon. As the freezing level continues to drop, a crust is expected to form at lower elevations . Ongoing southeast through southwest winds have been loading leeward features in the alpine and large cornice development has been reported over the last few days. The weak surface hoar layer from early January can be found down over a meter and is still reactive in isolated snowpack tests but triggering an avalanche on this layer has become unlikely.