The TRACK program automatically and objectively identifies suitablefeatures in time sequences of meteorological or oceanographic data.These features are then tracked through the time sequence to producefeature trajectories. These trajectories are then analysed to producestatistical diagnostic fields. These can then be used to aid the validationof General Circulation Models (GCMs) of the atmosphere and oceans which areused for forecasting and climate prediction. This approach can also be usedto study features such as tropical cloud complexes in observational data(satellites) and to generate climatologies from both model andobseravational data.