  A neural network combined to a neural classifier is used in a real time
forecasting of hourly maximum ozone in the centre of France, in an urban
atmosphere. This neural model is based on the MultiLayer Perceptron (MLP)
structure. The inputs of the statistical network are model output statistics of
the weather predictions from the French National Weather Service. With this
neural classifier, the Success Index of forecasting is 78% whereas it is from
65% to 72% with the classical MLPs. During the validation phase, in the Summer
of 2003, six ozone peaks above the threshold were detected. They actually were
seven.
