It may have been a white Christmas, but don't expect much change until we ho, ho, hopefully see some appreciable precipitation later in the week.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
TUESDAY: Mix of sun and cloud. Ridge wind light from the west. Temperature -4. Freezing level surface.WEDNESDAY: Mostly cloudy, flurries. Accumulation 5 cm. Ridge wind light to moderate from the southwest. Temperature -3. Freezing level surface.THURSDAY: Snow. Accumulation 15- 25 cm. Ridge wind moderate from the southwest. Temperature +1. Freezing level 1000 m.
Avalanche Summary
There have been no new reports of avalanche activity since last Wednesday when a natural Size 2 slab avalanche was reported on a southeast aspect at 1400 m on the North Shore mountains, as well as a Size 1 on a west aspect at 1200 m.
Snowpack Summary
A light dusting of new snow now covers the variable old surface consisting of; wind-scoured northwesterly slopes, areas of hard and soft wind slab on alpine lee slopes and exposed treeline areas, as well as a thin sun crust on steep solar aspects. Approximately 2-5 cm of new snow overlies 15-30 cm of old storm snow on top of the most recent December 18th melt-freeze crust, which has been unreactive in recent snowpack tests. Below this crusts lies 20 cm of well settled snow above the December 16th crust. Below this crust, a third crust, the 20 cm thick late-November crust, is now buried 40-50 cm. The lower snowpack well settled and moist to ground. Snowpack depths are about 135 cm at 1100 m elevation, with many early season hazards present at lower elevations.
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.