When rapidly growing thunderstorms appear enroute, a pilot makes many flight path decisions on the basis of his training and experience in the interpretation of radar echoes displayed in the cockpit. Echoes from more severe thunderstorms first appear at high-to-middle altitudes, and they possess other growth and decay characteristics that make their echoes distinguishable from the echoes of less severe thunderstorm types at various stages in their development. A color weather radar simulator can now be used to provide such training by modeling in four dimensions the dynamic growth characteristics of various thunderstorm types.