Predicting the Past

Shortly after the end of the Second World War, there was a strong interest in improving the accuracy of weather forecasts. The importance of this was clear: if you can accurately predict storms, or any type of adverse weather, you have a much better chance to prepare for its effects and stay safe. George Dyson1 wrote about this in Turing's Cathedral : "In 1945 meteorology had become a science, while forecasting remained an art....On average, forecasts beyond twenty-four hours were still no better than 'persistence'-predicting that the weather tomorrow will be the same as it was today."