Towards Numerical Prediction
Courageously, Richardson reported his results in his book Weather Prediction by Numerical Process, published in 1922. In one of the chapters of this work, Richardson describes a scheme for predicting the weather before it actually happens, a scheme involving a roomful of people, each computing separate sections of the equations, and a system for transmitting the results as needed from one part of the room to another. Unfortunately, Richardson’s estimated number of human calculators needed to keep pace with weather developments was 64,000, all located in one very large room. Richardson’s work highlighted the obvious fact that a large number of calculations had to be made very rapidly in order to produce a timely forecast. In the late 1940s, using one of the earliest modern computers, significant progress toward more practical numerical weather forecasts was made by a team of meteorologists and mathematicians at the Institute for Advanced Study (IAS) in Princeton, New Jersey. Mathematician John von Neumann (19031957, HungarianAmerican) directed the construction of the computer and put together a team of scientists led by Jule Charney (19171981, American) to apply the computer to weather forecasting. Charney determined that the impracticality of Richardson’s methods could be overcome by using the new computers and a revised set of equations, filtering out sound and gravity waves in order to simplify the calculations and focus on the phenomena of most importance to predicting the evolution of continentscale weather systems. In April 1950, Charney’s group made a series of successful 24hour forecasts over North America, and by the mid1950s, numerical forecasts were being made on a regular basis. 
Weather Forecasting Through the Ages
 
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