Two models are used at IRCELCELINE to forecast Ozone (O_{3}) concentrations :
SMOGSTOP  The computer model SMOGSTOP is a cluster of different statistical models. This model generates ozone (O_{3}) concentrations based on meteorological forecasts and historic time series of measured air pollution. The advantage of the SMOGSTOP model is the speed by which it can produce forecasts at specific locations. The disadvantage is that forecasts are only possible for locations where sufficient historic air pollution measurements are available. More information concerning the SMOGSTOP model developped by the VITO can be found in the article (pdf) published in the scientific journal "Environmetrics" and here.  
CHIMERE  The CHIMERE model is a deterministic model
that simulates the very complex fysical processes and chemical reactions in the
atmosphere based on meteorological forecasts, emissions of air pollutants and geograhical
landuse data. The advantage of deterministic models is the possibility to forecast air
pollution also at locations where the air quality is not measured. The disadvantage are
the complex input and the long computer calculation times (the last becomes less important
due to increasing computer calculation power) . The present resolution of the CHIMERE model is approximately 50x50 km, so the forecasted concentrations are representative for a large area. Real concentrations can be higher or lower on the local scale. More info concerning the (by IRCEL adapated) CHIMERE model can be found here. 

(click on the images for the most recent forecasts) 
Together with our own expertise, we use the SMOGSTOP and CHIMERE model results to inform the public for episodes with enhanced ozone pollution (summer smog). It is possible that the two models will procuce different forecasts. Interpreting the results is not always easy and they must be used carefully.