Avalanche Forecast
Issued: Dec 28th, 2018 3:54PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Low - Freezing levels are uncertain
Weather Forecast
FRIDAY NIGHT: Cloudy with isolated flurries, up to 10 cm accumulation. Light to moderate southwest wind. Alpine low of -12C.SATURDAY: Flurries, 5-15 cm accumulation. Moderate southwest wind gusting strong to extreme. Alpine high -4, freezing level rising above 1400 m.SUNDAY: Mix of sun and cloud with scattered flurries, trace to 5 cm accumulation. Light northwest wind gusting moderate to strong. Freezing level dropping to valley bottom, alpine high -3C.MONDAY: Mix of sun and cloud. Light northwest wind with occasional moderate gusts. Alpine low -15C.
Avalanche Summary
Small (size 1) wind slabs have been reactive to skier traffic in the region.A great MIN report from Corbin on Thursday identifies a few slabs initiating in thin, rocky areas on a south aspect. Check out the report here.Over the last weekend, the persistent weak layer was active, explosives triggered avalanches to size 2.5 and a cornice triggered a size 2 avalanche. Skier traffic was also able to trigger wind slab avalanches to size 2. Though avalanche activity on this layer has slowed, avalanches failing on this layer have the potential to be large and destructive.
Snowpack Summary
Around 20 cm fresh snowfall accumulated through the week has been redistributed around lee areas at treeline and alpine elevations. In total, 60-110 cm of snowfall through December has formed a slab that sits on a persistent weak layer that formed in early December. This layer mostly consists of facets (sugary snow) with some isolated areas also containing small surface hoar (feathery crystals). This overlies several other weak layers observed in the lower snowpack such as crusts and facets that formed in late October/early November. With this weak basal snowpack, it is likely that an avalanche triggered on the persistent slab would step down to these lower layers, resulting in a full depth avalanche.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 29th, 2018 2:00PM