Confidence
Fair - Forecast snowfall amounts are uncertain on Saturday
Weather Forecast
A warm front is forecast to move over the central and south coast on Friday night, bringing moderate precipitation and strong westerly winds. The winds are expected to peak at about 100 km/hr sometime in the early morning. Expect about 5-10 cm of snow overnight and another 5-10 cm during the day on Saturday. The freezing level on Saturday should rise to about 1200 metres. Snow is expected to continue on Sunday bringing another 5 cm and strong westerly winds. Periods of heavy snowfall are expected on Monday.
Avalanche Summary
A few size 1.0 avalanches were reported from Thursday. One was reported to have failed on a crust on a southerly aspect. Several reports of rider triggered size 1-2 avalanches occurred on Wednesday.
Snowpack Summary
The westerly winds have started to move any snow available for transport in the alpine, and at treeline. New windslabs are forming on North through East aspects, and old windslabs continue to linger on South through West aspects. A thin suncrust has formed on Southerly aspects. Reports of a preserved stellar layer exist down 20-40 cm. This layer has been reactive to rider triggers and should remain on your radar. Up to 60cm sits over a variety of old surfaces. These include melt-freeze crusts at lower elevations, old sun crusts on Southerly aspects into alpine elevations and spotty areas of surface hoar in sheltered treeline areas. The mid and lower snowpack is well bonded and strong.
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.
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.