Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Regions
Glacier.
This weekend an intense storm is forecast. Heavy precipitation, with rising freezing levels and strong winds, will increase danger. A widespread natural avalanche cycle is expected, with large avalanches running to valley bottoms.
Weather Forecast
There will be a brief break in the storms today, before an intense and moisture laden front hits this weekend. Today will be mostly cloudy with flurries. The alpine high is -2 and winds will be moderate but gusty from the SW. Sat and Sun are forecast to get up to 20cm a day, with freezing levels rising to 1600m by Sunday and strong SW winds.
Snowpack Summary
Up to 60cm of heavy snow over light snow has created a touchy soft slab. This lies on top of suncrusts on solar aspects, and windslab on N and E aspects. The new slab is failing with easy to moderate results within the new snow, as well as at the old interface. The Jan 28/Feb 10 PWLis down 1.2-1.5m under a cohesive slab.
Avalanche Summary
Artillery control over the past few days produced avalanches to size 3.5 running fast and to the end of their run-outs. Adjacent to the park, an avalanche on the Feb 10 PWL was 1.5m deep and up to 200m wide. Reports also indicate that the storm slab is becoming reactive to skier traffic on steep convex features.
Confidence
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.