Avalanche Forecast
Issued: Dec 17th, 2019 4:00PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeStorm snow continuing to accumulate will stress buried weak layers. Expect human triggered avalanches to be likely.
Summary
Confidence
Weather Forecast
TUESDAY NIGHT: Snow, accumulation 5-10 cm, moderate to strong southwest wind, alpine high temperature -6 C.
WEDNESDAY: Flurries, accumulation 5 cm, moderate southwest wind, alpine high temperature -4 C.
THURSDAY: Scattered flurries, moderate southwest winds, alpine high temperature -6 C.
FRIDAY: Flurries, moderate south wind, alpine high temperature -3 C.
Avalanche Summary
There was likely a natural avalanche cycle on Tuesday.
There was a report of a skier remotely (from a distance) triggered size 1.5 wind slab avalanche in the alpine on Sunday.
Snowpack Summary
30-60 cm of recent snow has accumulated above a widespread layer of large, feathery surface hoar crystals. New snow is expected to continue to accumulate and consolidate above this layer over the next few days, maintaining a high likelihood of human-triggering.
A weak layer formed in late November is now buried around 1 m plus below the surface. This is the layer of concern relating to the persistent slab avalanche problem. The weak layer may present as surface hoar, a crust, facets or a combination, depending on elevation and aspect. Below this, a variety of crusts from late October are buried deeper in the snowpack.
Problems
Storm Slabs
Snow accumulating above a buried layer of weak surface hoar has created a touchy storm slab problem. The conditions are primed for human triggered avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A couple of weak layers formed in late November and early December are now sitting about 1 m below the surface.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 18th, 2019 5:00PM