Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
South Coast.
Warm, wet and windy weather is expected to result in natural avalanche activity and increased danger.
Confidence
Fair - Due to the number of field observations
Weather Forecast
On Tuesday freezing levels are expected to rise as high as 2500 m as a Pacific frontal system brings up to 50 mm of precipitation and extreme southwesterly alpine winds. Wednesday is looking just as warm, windy, and wet. At this point, Thursday is looking slightly drier and cooler with freezing levels dropping below 2000 m and another 10-20 mm of precipitation as alpine winds shift to moderate southeasterlies.
Avalanche Summary
No new reports of avalanches. Please let us know what you're seeing out there at [email protected].
Snowpack Summary
Around 10-15 cm of moist then refrozen snow buried the previous variable snow surface that consisted of facets and large surface hoar in sheltered areas, or pockets of old wind slab and an ice crust in open wind-exposed terrain (depending on aspect). There are probably a couple notable crusts in the upper to mid snowpack. The deeper crust may be associated with a weak layer of facetted snow, but may be limited to slopes at and above treeline. One recent snowpack test on this layer in the northwest part of the region produced a sudden "pops" result down 80 cm on a north aspect at treeline. Snow pack depth and snow quality drastically diminishes as you drop below treeline.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.