- Contingency analysis (CA) is critical in many routine power system and market analyzes to show potential problems with the system. Due to the tremendous and yet increasing amount of data computed by CA, effective visualizations are needed to present the CA results to assist the system operators and engineers to comprehend the static security status of the system in a quick and intuitive manner. The desirable functionalities of such visualizations include showing the overall system security status, showing the severity levels of the contingencies in terms of their associated limit violations, and showing the geographic connection between the violated elements and the contingent elements. The traditional EMS display of CA results is a tabular list of elements with limit violations. This paper explores interactive three-dimensional visualizations for contingency data. We visualize vulnerability levels of power system elements and severity information of outages separately. The overall situation of the whole system is conveyed "at a glance" by the overview visualizations, while more detailed information is displayed as needed. 2004 IEEE.