I am looking for a dataset of ensemble forecasts and the associated true observed values. For example, a dataset containing $n$ ensemble forecasts of the temperature in 24 hours and the observed temperature 24 hours later. The ECMWF datasets look promising, but as a mathematician, I am not familiar with the terminology. Clicking on a dataset, this page for example, shows that "Analysis" and "Forecast" data is available. Are either of these the ensemble members or the observations? Downloading the data hasn't helped either.