A gust front is the leading edge of a thunderstorm outflow. A gust frontal passage is typically characterized by a drop in temperature, a rise in relative humidity and pressure, and an increase in wind speed and gustiness. Gust front detection is of concern for both Terminal Doppler Weather Radar (TDWR) and Next Generation Weather Radar (NEXRAD) systems. In addition, airborne systems using radar, lidar, and infrared sensors to detect hazardous wind shears are being developed. The automatic detection of gust fronts is desirable in the airport terminal environment so that warnings of potentially hazardous gust front-related wind shears can be delivered to arriving and departing pilots. Information about estimated time of arrival and accompanying wind shifts can be used by an Air Traffic Control (ATC) supervisor to plan runway changes. Information on expected wind shifts and runway changes is also important for terminal capacity programs such as Terminal Air Traffic Control Automation (TATCA) and wake vortex advisory systems. In addition, the convergence associated with gust fronts is often a factor in thunderstorm initiation and intensification. Knowledge of gust front locations, strengths, and movement can aid forecasters with thunderstorm-specific predictions. Current gust front detection systems generally are reliable in that the probability of false alarms is low. However the probability of detecting gust fronts with these systems is less than desired. Improved characterization of gust fronts is a key element in improving detection capability. Typically, the basic products from the algorithms are the location of the gust front (for hazard assessment) and its propagation characteristics (for forecasting). This paper discusses the thermodynamic and radar characteristics of gust fronts from three climatic regimes, highlighting regional differences and similarities of gust fronts. It also compares propagation speeds, estimated by two techniques, to measured propagation speeds.