Preliminary studies of Viking imager data by Lui et al. [1987> have revealed the presence, on occasion, of bright auroral structures periodically arrayed along the auroral oval in the post noon quadrant. It was suggested that these auroral forms reflect the action of a Kelvin-Helmholtz instability. In this paper we report the results of such a study of periodically arrayed auroral structures with concurrent ULF pulsations. Assuming a common origin of the two phenomena to be the Kelvin-Helmholtz instability, we make quantitative estimates of some key physical properties of the source region for the ULF and auroral disturbances. We further report the observation of a westward traveling surge in the vicinity of 18 MLT, and argue on the basis of the mapping factor from the ionosphere to the magnetotail why surges closer to midnight do not appear to exhibit a significant westward propagation velocity ¿ American Geophysical Union 1992