Avalanche Forecast
Issued: Dec 29th, 2018 4:21PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
SATURDAY NIGHT: Cloudy with isolated flurries and clear periods / Moderate northwest wind / Alpine temperature -6 CSUNDAY: Mostly cloudy with sunny breaks / Moderate northwest wind / Alpine temperature -7 C MONDAY: Mix of sun and cloud / Light north wind / Alpine temperature -5 CTUESDAY: Mainly Cloudy / Light west wind / Alpine Temperature -3 / Freezing level 700 m
Avalanche Summary
Recent avalanche activity has been reported as several explosives controlled size 2 storm and wind slabs in the alpine and tree line. Some of these avalanches were running on a layer of surface hoar buried around December 23. There was also a report of a size 3 wind slab avalanche that released sympathetically to an avalanche that was set of by an explosive about 30m away.
Snowpack Summary
40-50 cm of recent new snow sits on a weak layer of feathery surface hoar. Snow amounts will be deepest and touchiest in the lees of terrain features immediately adjacent to ridges.Below 1800 m, around 50 cm of storm snow may not be bonding well to an underlying crust (see here).A weak layer of sugary facets and surface hoar lies around 150 to 200 cm deep in the snowpack. There hasn't been reports of avalanches on this layer for over a week. That being said, this layer may still exist in isolated areas around treeline in some portions of the region.At the base of the snowpack, weak and sugary facets are found below an early-season melt-freeze crust. This weak layer has been the culprit for sporadic, very large avalanches in alpine terrain in the past few weeks. The avalanches have occurred in areas where the ground roughness is very smooth, for example glaciers, firn, and shale/rock slab slopes. An avalanche could be triggered in this layer with a very large trigger, such as a cornice fall.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 30th, 2018 2:00PM