While shoveling my deck, I'd penetrate the ice layer with my shovel and each time I heard a distinct "whomp" sound. If we receive the forecasted 5-8" of new snow tomorrow, I am concerned that the new snow will cause the ice layer to collapse and trigger slides of about 12" or more. The ice layer appears thicker at higher elevations, as the rain that fell over the weekend did not cool enough to turn to snow, but rather fell as rain and then froze as an ice layer above the very cold layers of snow below.
Observed Avalanche Problem #1:
This morning about 2 inches of loose snow was observed on both my shoveling and also at the Mazama parking area over a layer about 2-3 mm thick of pure ice, below which is unconsolidated snow for about 3-4 inches deep (depth hoar?). The ice layer is uniform and difficult to penetrate, but once penetrated there is "nothing" below it for 2-3 inches. The forecast for Tuesday 12/27 is for an additional 5-8" of warmer snow. I am concerned that the weight of the new snow may trigger collapse of the ice layer into the unconsolidated and weak layer of dry, cold snow below.