Avalanche Forecast
Issued: Dec 17th, 2018 4:07PM
The alpine rating is Storm Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeAdditional forecasted snow on an already over-loaded snowpack will keep the avalanche danger elevated. Conservative route choices are essential.
Summary
Weather Forecast
Two significant frontal systems are lined up to move inland over the next three days. 25-40 cm of additional new snow is expected along the divide by end of day on Thursday. This snow will be accompanied by moderate to strong SW winds. Freezing levels remain at valley bottom.
Snowpack Summary
40 - 60 cm of recent snow overrides a weak interface (Dec 10 layer) consisting of facets and surface hoar. Fresh windslabs can be expected on lee (north and east) aspects. The lower snowpack is weak and facetted. Any avalanches initiated in the storm snow have potential to step down to this lower layer.
Avalanche Summary
Numerous natural and skier (or explosive) triggered avalanches up to 2.5 have been reported over the past few days. Avalanches may run further down slope than expected, so be cautious of overhead hazard.
Confidence
Problems
Storm Slabs
Up to 50cm of recent snow with additional storm snow expected will have created storm slabs and wind slabs at all elevations. These slabs will be reactive to skier triggering. Ice climbers pay attention to overhead hazard.
Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
The mid and lower portions of the snowpack are weak and are now overloaded with critical levels of snow. We expect avalanches to step down to this deeper layer.
Good day to make conservative terrain choices.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 18th, 2018 4:00PM