Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain on Thursday
Weather Forecast
Synopsis: The South Coast remains largely high and dry Tuesday & Wednesday, but it looks like a change is in store for Thursday.Tuesday: Freezing Level: 800m Precip: Trace; Wind: Lht, NWWednesday: Freezing Level: 800m rising to 1000m; Precip: Trace; Wind: Light, NW.Wednesday Night: Precip: 2/8mm - 2/10cmThursday: Freezing Level: 1000m Precip: 10/25mm 10/30cm Wind: Strong SW at 2000m, extreme at ridgetop.
Avalanche Summary
No significant avalanche activity reported on Sunday.
Snowpack Summary
Winds were strong out of the west on Monday, but with limited snow available for transport I suspect the resultant wind slab to be limited to terrain immediately lee of ridgecrest. The older wind slab problem has been largely healed by a warm to cold temperature swing and a few days time. This pattern has resulted in a melt freeze crust below 1800m that now has a skiff of snow on it. Approx. 25-50cm below the surface you may find a variety of old surfaces which formed during the early December cold snap. These surfaces include sugary faceted snow (which may overlie a crust in some areas) and spotty surface hoar in sheltered terrain. In most places the overlying slab seems to be well bonded to this interface thanks to ongoing moderate temperatures.Snowpack depths vary greatly across the region, but are significantly lower than average for this time of year. Terrain below treeline is still mostly below threshold for avalanche activity. Early season riding hazards such as rocks, stumps and logs are lurking below the surface in many areas. In glaciated terrain new snow on the surface might be just enough to hide open crevasses where supportive snow bridges have not yet developed.
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.