Regions
South Coast Inland.
Wind slabs and cornices are the main concerns right now. Carefully assess terrain before committing to bigger lines.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're back to wet spring weather on Monday, and continuing throughout the forecast period. MONDAY: Rain (5-10mm) falling mostly after noon, with wet snow (5-10cm) above 1500m. Winds 20-30 km/h from the south.TUESDAY: Wet snow or rain (10-15mm / cm). Freezing level around 1700 m. Winds moderate southwesterly.WEDNESDAY: Rain (5-10mm) up to 1700m. Winds strong southerly.
Avalanche Summary
On Saturday, isolated small stiff wind slabs were reported on convex alpine features in the north of the region.
Snowpack Summary
Relatively light amounts of recent snow (10-20 cm in the past several days) resulted in isolated stiff wind slabs in the immediate lee of exposed terrain features at treeline and above. Dry snow can still be found on north aspects above 1900m; however, moist (or crusty) snow can be found on all south-facing slopes at all elevations.Cornices remain large in some areas and could trigger large avalanches when they fail (especially when warmed by the sun). The fatal accident near Lions Bay a week ago illustrates the danger of cornices breaking off, and the large avalanches they can trigger.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.