Sunday April 17, 2016

AccuWeather Issues 90-Day Forecasts, Meteorologists Not Amused

Three months? Hold your horses; I am not entirely convinced they can even get a 5-day forecast right.

A recent analysis found that a modern five-day forecast is as accurate as three-day forecast was in 1995. In the last three decades, thanks largely to numerical weather prediction, the useful window of forecasting has moved out from about 7 days to 10 days. Yet beyond 10 days, most meteorologists will say, there is little predictive skill. This is largely due to the "butterfly effect," in which only a very small change in initial conditions will have huge changes after about 10 days. However, in August of 2013, this basic mathematical principle didn't prevent AccuWeather from beginning to issue 45-day weather forecasts.