Long range forecast ensemble

The graph shows a cropped ensemble of model runs used to design a long-term forecast. Plotted here are 20 of the 40 members of the ensemble for temperature and precipitation. The temperature above and below the norm is marked with red and blue fill respectively. The amount of precipitation is plotted in green.

The ensemble allows you to see the possible range of variation in temperature and precipitation. In the average mode, general trends are visible, which are the basis for the long range weather forecast.