During daylight hours, avalanche danger is expected to remain LOW for all elevations and aspects. As snowfall intensity increases tonight, a significant increase in avalanche danger will occur with natural avalanche activity possible.
During the day today, avalanche concerns are few. Cloud cover built slowly last night and is expected to have allowed wet snow from yesterday a chance to refreeze. Precipitation rates today are expected to be light with new snow amounts of up to 1 inch forecast to accumulate during daylight hours. Significant avalanche problems of wind slabs and storm slabs are not expected to form until tonight.
After snowfall intensity increases tonight, natural and human triggered wind slab avalanches will become possible near and above treeline on NW-N-NE-E-SE aspects.
After snowfall intensity increases tonight, natural and human triggered storm slab avalanches will become possible. Areas where weak faceted snow exists at the old snow snow surface may cause new snow to bond poorly. In general snowpack failure is expected to occur at or above the old/new snow interface.
In general the existing snowpack is in good condition to handle new snow loading. A few specific areas with weak faceted snow at the current snow surface that will become the old/new snow interface have been observed.
Observations made yesterday on Lincoln Ridge (Yuba Pass area) revealed that the snow surface on north aspects below treeline that were sheltered from both sun and wind held up to 3 inches of near surface facets. These weak facets were sitting on top of a very thick, strong, and supportable rain crust. With a new slab of storm snow expected tonight, the possibility exists for a developing slab/weak layer/bed surface combination for storm slabs in below treeline terrain.
Other recent observation on Round Top Peak (Carson Pass area) and on Powderhouse Peak (Luther Pass area) noted that northerly aspect bed surfaces from slab avalanche activity Feb 8-9 hold several layers of weak faceted snow. With no overlying slab at this time, there is no current instability issue. As a slab of new snow is placed on top of these weak layers tonight, slab avalanche problems may arise.
