Abstract: Stereo particle image velocimetry measurements were performed downstream of a backward-facing step in a stationary-cross flow dominated flow. The PIV measurements exhibit excellent quantitative and qualitative agreement with the previously acquired hotwire data. Instantaneous PIV snapshots reveal new information about the nature and cause of the spikes” that occurred prior to breakdown in both the hotwire and PIV data. The PIV snapshots show that the events occur simultaneously across multip…