Regions
South Coast Inland.
Storm slabs 20 to 40 cm in depth may remain problematic Monday. Choose wind sheltered terrain features while minimizing exposure to both cornices and overhead avalanche paths, the late winter sun packs a punch and could initiate natural avalanches.
Weather Forecast
The work week kicks off with a rather disorganized pattern that is not expected to generate any significant snowfall, but a significant change looks to be in store as a vigorous low approaches the South Coast Inland region Wednesday evening.MONDAY: A few clouds, freezing level around 700 m, light west/northwest wind, no significant snowfall expected. TUESDAY: Scattered cloud cover, freezing level around 900 m, moderate to strong west wind, trace of snow possible.WEDNESDAY: Overcast, freezing level around 900 m, potentially strong to extreme south/southwest wind, copious amounts of precipitation possible, but the latest model run shows about 10 cm of snow. Stay tuned for more details.
Avalanche Summary
Small wind slabs failed naturally and were human triggered Saturday to size 1 on south and southeast facing features between 1750 and 1900 m.
Snowpack Summary
10 to 20 cm of storm snow fell Friday night and another 12 to 25 cm fell Saturday night into Sunday. The successive storms were accompanied by strong winds out of the south, southwest, west and northwest. Wind stiffened storm slabs will likely be found in upper elevation terrain and this snow may not be bonding well to the old surface. In the southern portion of the region a widespread crust is down 40 to 80 cm below the surface. Well-consolidated snow exists below the crust.Variable winds in the past month have created cornices on all aspects in the alpine. They will become touchier as they grow in size, as temperatures rise, and as the sun shines down upon them 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.