This is interesting. It is not 100% clear to me what the measure of accuracy is below, but the plot shows how much weather forecasting has improved over the last 50 years or so. A 3-5 day forecast is highly accurate now, and 3-5 are not that different. It’s interesting to me that there is such as large drop off in accuracy between a 7 and 10 day forecast – that is not necessarily intuitive, but useful even in everyday life. A 10-day forecast is basically a coin flip, while check back 3 days later and you are closer to 80/20 odds. This is based on pressure measured at a certain height I think, so it doesn’t necessarily mean forecasts of precipitation depth and intensity, rain vs. snow vs. ice, thunder and lightning, tornadoes, etc. are going to be as accurate as this implies.

There is some suggesting that AI (meaning purely statistical approaches, or AI choosing any blend of statistics and physics it wants?) might make forecasting much faster, cheaper, and easier yet again.