This paper examines the evolution of the Dvorak technique for estimating the intensity of tropical cyclones from satellite imagery. This pattern-recognition technique was originally developed in the early 1970's based on once daily visible imagery for tropical cyclones in the Atlantic and northwestern Pacific. It subsequently has evolved to include infrared imagery, animation, and other advances in satellite data and display capabilities. The technique is now in use worldwide and has stood the test of time for 30 years - no methodology has yet proved superior enough to replace it. The paper also examines various present and future extensions of the technique such as the Objective Dvorak Technique and possible use of microwave data.