Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
South Coast.
Wednesday's storm produced 20 to 40 cm accompanied by east wind, which has likely formed storm slabs in unusual locations. Keep a close eye on the effects of the strong sun Friday, it could initiate natural avalanche activity very quickly.
Confidence
Low - Timing or intensity of solar radiation is uncertain on Friday
Weather Forecast
There is potential for a few more centimeters of snow on Friday, and then we move into a high and dry period. No significant precipitation is expected for the foreseeable future. FRIDAY: Clear skies in the morning, cloud building throughout the day, freezing level around 600 m, light east wind, 2 to 5 cm of snow possible.SATURDAY: A few clouds, freezing level rising to around 1000 m, light northeast wind, no precipitation expected.SUNDAY: A few clouds, freezing level rising to around 1200 m, light west/northwest wind, no precipitation expected.
Avalanche Summary
No new activity to report from Wednesday, but we suspect that a small natural storm slab avalanche cycle occurred. On Tuesday storm slab avalanches up to 15 cm in depth were very touchy and sensitive to ski cutting, check out these two MIN reports here and here.
Snowpack Summary
The region picked up 20 to 40 cm of snow Wednesday and Thursday with moderate winds out of the east/southeast. This adds to the 50 to 70 cm that fell between Saturday and Tuesday. All of this snow rests on previously wind-affected surfaces and a sun crust on southerly aspects.A hard rain crust that extends into alpine terrain is buried about 60 to 120 cm deep. There are no substantial weak layers below the crust.Cornices have formed on many alpine ridgelines. They will become touchier as they grow in size, as temperatures rise, and as they are subject to the strong mid-winter sun on clear days.
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.