Persistent high pressure over California has kept storm systems from entering the Sierra for some time now. Temperatures have remained well above seasonal averages and the snowline has crept ever higher. Northerly slopes continue to have far better coverage than south-facing areas. These calm conditions have created a thin and weak snowpack compared to what we usually expect. Layers of soft, sugary, faceted snow have been observed on north-facing slopes from Mammoth to Virginia Lakes. The most concerning layers lie between 10 and 40cm under the surface, and again just above ground level. In sheltered areas, facets remain exposed on top of the snowpack. Testing these layers has been a mixed bag with some places failing easily under stress while other places have not shown much sensitivity. What does that means for us, as the ridge over the west coast begins to flatten and there becomes potential for new snowfall? It means that the avalanche danger could rise quickly with significant new loading and could be difficult to predict. Stay tuned as the chances of more winter weather increase.
Until temperatures and storm patterns return to something resembling normal, areas south of Mammoth and elevations below ~9500’ will have poor snow coverage. Southerly slopes are mostly bare, or have melt-freeze snow resembling spring conditions – even above 10,000’. Early season obstacles remain exposed or hidden just under the surface on most slopes you want to ride. Firm wind board and breakable crust can make descending northerly slopes challenging. Have fun out there, but stay safe.