Wind-driven snow will increase the avalanche danger on Sunday. Watch for how the new snow is bonding to the old surface.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday
Weather Forecast
After a long drought we'll see some new snow, blown in by southwest winds. SUNDAY: Snow. Accumulation 10-15 cm. Ridge wind moderate from the southwest. Freezing level 1000 m.MONDAY: Cloudy, flurries. Accumulation up to 5 cm. Ridge wind light from the west. Freezing level 700 m.TUESDAY: Snow. Accumulation up to 10-20 cm. Ridge wind moderate from the south west. Freezing level 800 m.
Avalanche Summary
No new avalanches reported.Avalanche activity is expected to increase with the wind-driven snow on Sunday, especially on north through east aspects at higher elevations.
Snowpack Summary
A light dusting of new snow covers the melt-freeze crust that formed on all aspects and elevations. On north aspects this crust is thin with dry, sugary snow crystals (facets) below. Beneath the surface, the upper snowpack is well settled and overlies a thin layer of facets on the late-November rain crust. Snowpack tests found hard, sudden compression test results on the facets just above the crust, which is now down approximately 50 cm at tree line elevations. The lower snowpack is well settled and consists of several crusts that formed in the early season.
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.