Weather forecasting has long been a mix of science and intuition. You knew it would rain, but you didn't know exactly when. You knew the heat wave was coming, but not how brutal it would be. Between the two there was always an almost philosophically accepted margin of error: "that's the weather.” Today, that margin is starting to thin. It's not disappearing, but it's being compressed in a way that meteorologists are no longer just talking about clouds and atmospheric pressure, but about digital