Storm slabs are the main concern in the north of the region (Sky Pilot area) while loose wet avalanches are the main concern in the south (North Shore mountains). Continually reassess conditions as you travel.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Wednesday
Weather Forecast
We're looking at unsettled and variably wet spring weather through Thursday, with clearing and fine weather for Friday.WEDNESDAY: More wet snow (10-15cm) above 1400m. Winds moderate southerly.THURSDAY: Flurries continue (5-10cm) with wet snow above 1500m. Winds light southwesterly.FRIDAY: Sunny with cloudy periods. Freezing level rising to 2100m. High temperatures to +9 Celsius. Winds light southerly.
Avalanche Summary
No new avalanches reported, but there have been limited observations lately.
Snowpack Summary
On Monday into Tuesday we had 40mm of precipitation in the North Shore Mountains, most of which fell as rain to the summits. In the Sky Pilot area, 20-30cm of snow likely fell above 1600m, forming storm slabs in the process. Southerly aspects at treeline and below contain moist snow: Loose wet avalanches remain a concern in this elevation band. Cornices remain large in some areas and could trigger large avalanches when they fail (especially when warmed by the sun, or drenched by rain). Additionally, cornices present a falling hazard and should be given a wide berth while traveling on ridgetops.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
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.