Rising Avalanche Danger 12-30-04                                                                                                        (Steep Hollow-Crescent Lake Canyon)

                                                     Dave Kikkert witnessing substantial wind-drifting on an exposed ridge.

              Strong winds can deposit fresh snow well off ridgelines. High winds and heavy snowfall cause deep slabby accumulations over broad areas.

                                 We triggered several of these small soft slab avalanches by dropping cornices on steep slopes below.

                                          This avalanche on a 38 degree north facing slope was about a foot deep and 40 feet wide.

                                Test pits showed a slab layer building on a thin sugary week layer overlying a smooth and solid rain-crust.

                                                     The cohesive slab would easily fail as a unit on small faceted crystals.

                       This kind of cracking indicates an instability that will only get worse with additional accumulation of wind-blown snow.

                  In this image you can see an obvious color difference between the forming slab and the weak sugary weak layer.